...All Things Vero...
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- Start date
stardustsailor
Well-Known Member
Clifford D. Ferris
22.1.1 Introduction
Human tissues, such as the skin and the muscles, as well as blood and other body fluids are classified as
electrolytes. Consequently, they are electrical conductors that may be characterized in terms of ohmic
resistances. Electric potential differences applied across human tissues, or at two locations on the external
skin surface, generate response currents.
Electric shock can be divided into two classes: microshock and macroshock. Microshock describes an
internal shock that may occur as a consequence of certain medical diagnostic procedures (such as cardiac
catheterization) or surgical procedures inwhichelectrically operated sensors are introducedintothehuman
body. Electric current levels associated with microshock range from 10 to 100 μA. This phenomenon is
specific to medical procedures and will not be addressed further in this chapter.
Macroshock, or simply electric shock, describes simultaneous contact between the body surface and
two electrical conductors at different potentials, and the physiological consequences of this contact. The
two conductors may be a hot conductor and ground, or two hot conductors, such as two of the phase wires
in a three-phase power distribution system.
The severity of the consequences of electric shock depends on a variety of factors. The physiological
effects of electrical shock are not produced by electric potential (voltage) per se, but rather by the electric
current that is driven by the potential difference that is applied externally to the body surface.Consequently,
the combined effective electrical resistance of the body volume involved and the intimacy (surface area
and pressure) of the skin-conductor contact have a major effect on the severity of electric shock. The
paths through the body that the shock currents take determine the potential seriousness of the shock.
Generally speaking, current paths that do not include the head or main trunk of the body are not fatal,
although permanent damage may be produced in the formof scars, nerve ormuscle impairment resulting
in partially or fully paralyzed limbs, and loss of limbs. Electric shock currents that pass through the chest
in the region of the heart or lungs may cause death, either by direct effect on the heart, or by paralysis
of the nerves that control the breathing diaphragm. Severe electric shocks to the head may cause death
or permanent brain damage. As illustrated in Fig. 22.1, the two most dangerous current paths are from
hand-to-hand, and hand-to-foot (especially left hand to left foot) since the current passes through the
chest and potentially through the heart.
Response to electric shock is subjective to some extent, with both physiological and psychological
components. The condition of the skin surfaces that come into contact with the electrical conductors is
an important factor. For example, if an adult grasps the probes of a digital ohmmeter tightly between the
thumb and forefinger of each hand, the resistance displayed will vary widely among individuals. Those
individuals who use their hands in activities that build up callouses may produce resistance readings on
the order of 1 or 2 M when the hands are dry, and perhaps 100 k when the hands are wet. Other
individuals with soft and pliant skin may register 5–10 k with dry hands and significantly lower values
when the hands are moist or wet. If the ohmmeter is powered by a 9-V battery, the maximum possible
current sustained in the1-Mcase is 9μA, whereas it is 0.9mAwhen the resistance is 10 k(a thousandfold
increase).
The sensation experienced by individuals exposed to the same low level of electric shock varies widely.
Reported sensations range from buzzing, tingling (pins and needles), to burning or a jolt. The emotional
state of the individual at the time that the shock was received and the body location of the shock also
influence response. Shock response tends to be amplified in persons who are tense. If the shock site is
near a nerve or nerve ending that is close to the surface of the skin, the perceived intensity of the shock is
also amplified. A parallel situation is bumping one’s elbow and triggering the funny-bone response. The
physiological consequences of electric shock at different current levels (rms) for alternating current at
60 Hz are presented in Table 22.1. Threshold levels are shown. Refer to the section on Physiological Effects
for additional information.
There are various secondary effects of electric shock that can cause serious injury even if the shock itself
has produced no direct physiological damage. As with any sudden and unexpected sensory stimulus, the
startle reflex may be triggered causing the person to fall down, flail limbs, drop objects, or otherwise sustain
injury. High potentials, especially those produced by the discharge of a high-voltage capacitor, can induce
severe and generalized muscle contractions of sufficient intensity to propel an individual across a room.
Because of the violence of the reaction, the person may sustain serious bone fractures (or even death) as a
consequence of physical impact with objects in the trajectory path from the site of the shock. Even if the
victim does not collide with an object, the force of the muscle contractions alone resulting from electrical
shock may fracture spinal vertebrae or cause a shoulder dislocation.
stardustsailor
Well-Known Member
22.1.2 Physiological Effects
As can be inferred from Table 22.1, the medical consequences of electric shock range in severity from no
effect through minor burns, nerve and muscle damage, to death. Determining factors are
1. Effective electrical resistance of the body between the contact points
2. Portion of the body involved in the current path
3. Nature of the electrical source producing the shock
4. Body weight
Items 1 and 2 have been addressed to some extent in the Introduction. The lower the contact resistance,
the higher is the resulting shock current and the possibility of severe damage. A current path through
the body trunk is potentially the most lethal. The electrical resistance of the human body is a function
of frequency. By a strange quirk of nature, it is lowest at 60 Hz and rises slightly as frequency decreases
to 0 Hz or DC. The resistance also rises as frequency increases above 60 Hz. At frequencies on the order
of 100 kHz, skin-surface (capacitance) effects commence such that electric conduction paths include the
skin surface as well as bulk effects through the underlying body tissues. A shock that exceeds the let-go
threshold is particularly dangerous because the victim begins to perspire, which then reduces the contact
resistance between the body and the electrical source. When the contact resistance decreases, the shock
current increases. The let-go threshold current level in women is about 30% lower than in men and may
relate to differences in skin condition and resistance.
Generally speaking with regard to item 3, the effects of alternating current shock are more severe than
direct current shock at the same current levels (rms and DC). The sensation level for DC is about 5 mA,
as opposed to 1 mA (rms) for AC at 60 Hz. The let-go threshold shown in Table 22.1 for AC at 60 Hz is
10–20 mA (15 mA average). For DC, the let-go threshold is on the order of 75 mA, a figure that is higher
than the corresponding maximum peak-to-peak AC value at the 20-mA rms level.When there is a direct
current path through the heart, a momentary current of 60 mA (rms) at 60 Hz can induce ventricular
fibrillation (defined subsequently), whereas a direct current in the range from 300 to 500 mA is required.
A sustained shock at 120 V AC and 60 Hz is especially dangerous. The body resistance is at a minimum
and the voltage level is not high enough to cause severe muscle contractions that might otherwise propel
the victim away from the electrical source.
As is discussed in the next section, electrical current that passes through the chest region may cause
cardiac arrest. The intensity of the current required to produce this condition is a function of the time in
the cardiac cycle atwhich the shock occurs and, to some degree, the victim’s bodyweight.Heavy individuals
present larger chest volumes, and the current paths are presumably more diffuse than the current paths
through the chest region of a slender person.
Body Trunk (Heart and Lungs)
The human body runs on electricity. Sensory information received from our environment is translated
into electrical pulses that are transmitted along nerve pathways to the brain. Muscle activity is initiated
by electrical pulses that pass along nerves to sites called myoneural junctions where they trigger a muscle
to extend or contract. From a mechanical point of view, the heart is simply a four-chambered pump
composed of muscular tissue, as indicated in Fig. 22.2 (as viewed externally from the front).
The two upper chambers (left and right atria) are reservoirs that hold the blood that is returned to the
heart from the body organs and the lungs. The main pump chambers are the left and right ventricles.
The atrial chambers supply blood to the ventricles. When the ventricles (ventricular muscles) contract
producing a heart beat, blood from the left ventricle is pumped through the aorta to the body organs (the
systemic circulation); blood from the right ventricle is pumped through the pulmonary artery to the lungs
(the pulmonary circulation). The beating of the heart is controlled by an electric pacemaker (analogous
to a free-running multivibrator), called the sinoatrial or SA node, which is composed of a small volume
of specialized tissue located at a site toward the top of the heart. The pacemaker generates regular pulses
that cause the muscles of the ventricles to contract (one pulse per heart beat). In the normal heart, the
pacemaker adjusts its output frequency according to the body’s demand for oxygen.
The contraction and relaxation of muscles also generates electrical pulses. The beating of the heart is
controlled by pulses from the pacemaker, while at the same time the contraction and relaxation of the
heart-muscle tissues generate electrical pulses. Because the body is a volume conductor, these pulses can
be detected on the surface of the body and recorded as an electrocardiogram(ECG). If a sensing electrode
is placed on the inside of each wrist with a third reference electrode on the inside of the right ankle, a signal
of the formshown in Fig. 22.3 can be obtained. The signal shown represents one cardiac cycle (heart beat)
in a normal heart and is designated as Lead II in the standard method of recording electrocardiograms.
The time axis has been normalized to unity, and the major events (called waves) are denoted by P, Q, R, S,
T, and U. The maximum peak value (R wave) on the skin surface is approximately 1.5 mV, although values
on the order of 1 mV are usually recorded. The P wave represents the muscular contraction of the atrium
(two atrial chambers) to force blood into the ventricles. The R wave (in the QRS complex) represents the
contraction of the ventricles and the pumping of blood out of the heart into the aorta and pulmonary
artery. The T wave is generated by the relaxation (called repolarization) of the ventricular muscles. The
electrical signal from the relaxation of the atrium is masked by the high-intensity R wave.
A severe shock current that passes through the chest cavity will cause the entire heartmuscle to contract
and stop beating while the current persists. If such a current is of short duration, normal heart rhythm
begins again with no irreversible cardiac tissue damage. Lower levels of current can disrupt normal heat
rhythm. The heart is most susceptible to electric shock during the occurrence of the T wave. Thus a current
that just produces a shock response during the T wave typically will not generate any effect during another
period of the cardiac cycle. The response of a normally beating heart to an above-threshold electric shock
current is cardiac arrest.
The gross symptoms of cardiac arrest produced by electric shock are an unconscious subject who
is not breathing, has no detectable pulse (cardiac arrest), and zero blood pressure. The heart, however,
may be in either one of two states: standstill or ventricular fibrillation. In standstill, as the name
implies, the heart is not beating and the ECG signal is a flat line. In fibrillation, the ventricular muscle
groups contract randomly and out of unison such that the ventricles flutter. No blood is pumped, but a
low-level electrical signal is produced. An ECG recorder is required to differentiate between flat line and
ventricular fibrillation (VFIB). The respective ECG signals are illustrated in Fig. 22.4.
A shock current that passes throughthe chest regionmay cause involuntary contraction of the respiratory
muscles. The subject can no longer breathe voluntarily, and asphyxiation occurs if the current is not
interrupted. Respiratory paralysis (cessation of breathing) may occur as a consequence of electric shock
that takes a pathway through the body trunk.Typically,what occurs is the nerve that controls the diaphragm
is paralyzed.When the shock occurs, the subject inhales sharply and the chest expands and then becomes
rigid, even after the electric current has ceased. The heart may or may not be affected. In some cases, the
heart initially continues to beat normally until the beats become erratic because the heart muscle itself is
no longer receiving properly oxygenated blood. CO2 builds up in the blood and produces acidosis, which
causes irritability of the heart-muscle tissue and makes restoration of the normal heart beat difficult.
As can be inferred from Table 22.1, the medical consequences of electric shock range in severity from no
effect through minor burns, nerve and muscle damage, to death. Determining factors are
1. Effective electrical resistance of the body between the contact points
2. Portion of the body involved in the current path
3. Nature of the electrical source producing the shock
4. Body weight
Items 1 and 2 have been addressed to some extent in the Introduction. The lower the contact resistance,
the higher is the resulting shock current and the possibility of severe damage. A current path through
the body trunk is potentially the most lethal. The electrical resistance of the human body is a function
of frequency. By a strange quirk of nature, it is lowest at 60 Hz and rises slightly as frequency decreases
to 0 Hz or DC. The resistance also rises as frequency increases above 60 Hz. At frequencies on the order
of 100 kHz, skin-surface (capacitance) effects commence such that electric conduction paths include the
skin surface as well as bulk effects through the underlying body tissues. A shock that exceeds the let-go
threshold is particularly dangerous because the victim begins to perspire, which then reduces the contact
resistance between the body and the electrical source. When the contact resistance decreases, the shock
current increases. The let-go threshold current level in women is about 30% lower than in men and may
relate to differences in skin condition and resistance.
Generally speaking with regard to item 3, the effects of alternating current shock are more severe than
direct current shock at the same current levels (rms and DC). The sensation level for DC is about 5 mA,
as opposed to 1 mA (rms) for AC at 60 Hz. The let-go threshold shown in Table 22.1 for AC at 60 Hz is
10–20 mA (15 mA average). For DC, the let-go threshold is on the order of 75 mA, a figure that is higher
than the corresponding maximum peak-to-peak AC value at the 20-mA rms level.When there is a direct
current path through the heart, a momentary current of 60 mA (rms) at 60 Hz can induce ventricular
fibrillation (defined subsequently), whereas a direct current in the range from 300 to 500 mA is required.
A sustained shock at 120 V AC and 60 Hz is especially dangerous. The body resistance is at a minimum
and the voltage level is not high enough to cause severe muscle contractions that might otherwise propel
the victim away from the electrical source.
As is discussed in the next section, electrical current that passes through the chest region may cause
cardiac arrest. The intensity of the current required to produce this condition is a function of the time in
the cardiac cycle atwhich the shock occurs and, to some degree, the victim’s bodyweight.Heavy individuals
present larger chest volumes, and the current paths are presumably more diffuse than the current paths
through the chest region of a slender person.
Body Trunk (Heart and Lungs)
The human body runs on electricity. Sensory information received from our environment is translated
into electrical pulses that are transmitted along nerve pathways to the brain. Muscle activity is initiated
by electrical pulses that pass along nerves to sites called myoneural junctions where they trigger a muscle
to extend or contract. From a mechanical point of view, the heart is simply a four-chambered pump
composed of muscular tissue, as indicated in Fig. 22.2 (as viewed externally from the front).
The two upper chambers (left and right atria) are reservoirs that hold the blood that is returned to the
heart from the body organs and the lungs. The main pump chambers are the left and right ventricles.
The atrial chambers supply blood to the ventricles. When the ventricles (ventricular muscles) contract
producing a heart beat, blood from the left ventricle is pumped through the aorta to the body organs (the
systemic circulation); blood from the right ventricle is pumped through the pulmonary artery to the lungs
(the pulmonary circulation). The beating of the heart is controlled by an electric pacemaker (analogous
to a free-running multivibrator), called the sinoatrial or SA node, which is composed of a small volume
of specialized tissue located at a site toward the top of the heart. The pacemaker generates regular pulses
that cause the muscles of the ventricles to contract (one pulse per heart beat). In the normal heart, the
pacemaker adjusts its output frequency according to the body’s demand for oxygen.
The contraction and relaxation of muscles also generates electrical pulses. The beating of the heart is
controlled by pulses from the pacemaker, while at the same time the contraction and relaxation of the
heart-muscle tissues generate electrical pulses. Because the body is a volume conductor, these pulses can
be detected on the surface of the body and recorded as an electrocardiogram(ECG). If a sensing electrode
is placed on the inside of each wrist with a third reference electrode on the inside of the right ankle, a signal
of the formshown in Fig. 22.3 can be obtained. The signal shown represents one cardiac cycle (heart beat)
in a normal heart and is designated as Lead II in the standard method of recording electrocardiograms.
The time axis has been normalized to unity, and the major events (called waves) are denoted by P, Q, R, S,
T, and U. The maximum peak value (R wave) on the skin surface is approximately 1.5 mV, although values
on the order of 1 mV are usually recorded. The P wave represents the muscular contraction of the atrium
(two atrial chambers) to force blood into the ventricles. The R wave (in the QRS complex) represents the
contraction of the ventricles and the pumping of blood out of the heart into the aorta and pulmonary
artery. The T wave is generated by the relaxation (called repolarization) of the ventricular muscles. The
electrical signal from the relaxation of the atrium is masked by the high-intensity R wave.
A severe shock current that passes through the chest cavity will cause the entire heartmuscle to contract
and stop beating while the current persists. If such a current is of short duration, normal heart rhythm
begins again with no irreversible cardiac tissue damage. Lower levels of current can disrupt normal heat
rhythm. The heart is most susceptible to electric shock during the occurrence of the T wave. Thus a current
that just produces a shock response during the T wave typically will not generate any effect during another
period of the cardiac cycle. The response of a normally beating heart to an above-threshold electric shock
current is cardiac arrest.
The gross symptoms of cardiac arrest produced by electric shock are an unconscious subject who
is not breathing, has no detectable pulse (cardiac arrest), and zero blood pressure. The heart, however,
may be in either one of two states: standstill or ventricular fibrillation. In standstill, as the name
implies, the heart is not beating and the ECG signal is a flat line. In fibrillation, the ventricular muscle
groups contract randomly and out of unison such that the ventricles flutter. No blood is pumped, but a
low-level electrical signal is produced. An ECG recorder is required to differentiate between flat line and
ventricular fibrillation (VFIB). The respective ECG signals are illustrated in Fig. 22.4.
A shock current that passes throughthe chest regionmay cause involuntary contraction of the respiratory
muscles. The subject can no longer breathe voluntarily, and asphyxiation occurs if the current is not
interrupted. Respiratory paralysis (cessation of breathing) may occur as a consequence of electric shock
that takes a pathway through the body trunk.Typically,what occurs is the nerve that controls the diaphragm
is paralyzed.When the shock occurs, the subject inhales sharply and the chest expands and then becomes
rigid, even after the electric current has ceased. The heart may or may not be affected. In some cases, the
heart initially continues to beat normally until the beats become erratic because the heart muscle itself is
no longer receiving properly oxygenated blood. CO2 builds up in the blood and produces acidosis, which
causes irritability of the heart-muscle tissue and makes restoration of the normal heart beat difficult.
stardustsailor
Well-Known Member
Tissue Damage
Except for very minor electric shocks, burns may be expected at the contact site(s) with the involvement
of the skin surface and underlying tissues as a consequence of the penetration by the electric current.
Traditional descriptions of the severity of thermal burns includes first-, second-, and third-degree burns.
Some medical personnel have designated severe burns produced by electrical shock as fourth degree.
First-degree burns are essentially superficial and are described by discoloration or redness of the skin, mild
swelling, and associated pain. In subjects without underlying medical problems (such as diabetes), they
normally heal quickly and without complications. Second-degree burns penetrate more deeply into the
skin tissues than first-degree burns to produce a red or mottled appearance with blister formation and
significant pain. Considerable swelling of the affected area occurs over a period of a few days, and the skin
surface is usually wet from a loss of plasma from the damaged skin layers.
Third-degree burns involve deep penetration of the skin, frequently into underlying tissue, with coagulation
of the skin, destruction of red blood cells, and charring of the skin. Initially the skin surface may
appear white or charred, or it may resemble a second-degree burn. The risk of infection at the burn site is
high, and full healing of the skin may occur only at the edges of the burned area with scar tissue replacing
normal skin tissue in the main area of the injury.
The classification fourth-degree burn has been applied to electrical burns that char the overlying tissues
in a manner that an underlying bone is exposed. This is the type of injury that can be produced by contact
with high-voltage transmission lines. If death does not occur fromthe shock, permanent physical disability
can be expected.
Whatever the apparent degree, burns resulting fromelectrical shock should not be taken lightly.With the
exception of severe fires and explosions, accidental thermal burns typically affect the skin because they are
produced by some hot object or liquid that contacts the skin surface. On the other hand, burns produced
by electrical shock result from the passage of current through the skin and underlying tissues. Skin damage
may appear to be slight, but there may be extensive tissue damage below the skin surface. Burns associated
with electric shock tend to be deep, slow to heal, and subject to infection if not treated immediately. In
some cases, both thermal and electrochemical burns can occur simultaneously if the subject accidentally
touches an electrically energized hot conductor such as heating coil in an electric oven.
Depending on the nature of the electric shock, the tissues involved can be heated to temperatures as
high as 5000◦C, thus converting the water content of the body cells and fluids to superheated steam. There
is progressive necrosis (death) and sloughing of the affected tissues. Damage is generally greater than that
inferred fromthe initial examination of the burned area. This situation occurs because the electric current
penetrates into the body, whereas thermal burns, such as those from contact with hot liquids or solid
surfaces, generally occur at the body surface. The heat produced by the passage of electric current through
biological tissues coagulates proteins, ruptures cells, and produces tissue death.When nerve and/ormuscle
tissues are involved, permanent effects may be expected that vary from partial impairment of function of
the limb(s) involved to complete paralysis.
Biological tissuesmay be modeled electrically as parallel resistance-capacitance circuits. ForDCand lowfrequency
AC currents, the resistive component controls the current levels produced by electric shocks. At
audio frequenciesandabove, capacitive reactancedecreases tovalues comparable tothe resistive component
of the tissue electrical impedance. This situation leads to the potential of very deep and searing burns when
electric shock currents pass through tissues. The effects of high-frequency current are put to beneficial use
in the now widely used electrosurgical apparatus (electrical scalpel). These instruments typically operate
in the 300–400 kHz range, and by modulating the wave form of the signal, surgical cutting, cauterizing,
or a combination of the two may be achieved.
GG,although you seem not to be affected ,do not try that ever again.
We love you ,man...
We need you .As,other people need you alive ,too I'm pretty sure ..
Take care ,man.
WTF ? Are you the dude from "jack-ass " who 's still alive ?
Cut the crap man,that's some serious shit ...
I like you being on that Earth,dude..
Do not act opposite,please..
Small favor,for me ?
Note : It's high frequency pulsed DC actually ...
(switching constant current power supply output )
But you never know..
Once ,shit will happen ...
No chance for "twice" ...
Not in this 'ride' ,at least ...
DO NOT TAKE RISKS.
Playing Russian Roulette with wires & pins ,FGS !!
Except for very minor electric shocks, burns may be expected at the contact site(s) with the involvement
of the skin surface and underlying tissues as a consequence of the penetration by the electric current.
Traditional descriptions of the severity of thermal burns includes first-, second-, and third-degree burns.
Some medical personnel have designated severe burns produced by electrical shock as fourth degree.
First-degree burns are essentially superficial and are described by discoloration or redness of the skin, mild
swelling, and associated pain. In subjects without underlying medical problems (such as diabetes), they
normally heal quickly and without complications. Second-degree burns penetrate more deeply into the
skin tissues than first-degree burns to produce a red or mottled appearance with blister formation and
significant pain. Considerable swelling of the affected area occurs over a period of a few days, and the skin
surface is usually wet from a loss of plasma from the damaged skin layers.
Third-degree burns involve deep penetration of the skin, frequently into underlying tissue, with coagulation
of the skin, destruction of red blood cells, and charring of the skin. Initially the skin surface may
appear white or charred, or it may resemble a second-degree burn. The risk of infection at the burn site is
high, and full healing of the skin may occur only at the edges of the burned area with scar tissue replacing
normal skin tissue in the main area of the injury.
The classification fourth-degree burn has been applied to electrical burns that char the overlying tissues
in a manner that an underlying bone is exposed. This is the type of injury that can be produced by contact
with high-voltage transmission lines. If death does not occur fromthe shock, permanent physical disability
can be expected.
Whatever the apparent degree, burns resulting fromelectrical shock should not be taken lightly.With the
exception of severe fires and explosions, accidental thermal burns typically affect the skin because they are
produced by some hot object or liquid that contacts the skin surface. On the other hand, burns produced
by electrical shock result from the passage of current through the skin and underlying tissues. Skin damage
may appear to be slight, but there may be extensive tissue damage below the skin surface. Burns associated
with electric shock tend to be deep, slow to heal, and subject to infection if not treated immediately. In
some cases, both thermal and electrochemical burns can occur simultaneously if the subject accidentally
touches an electrically energized hot conductor such as heating coil in an electric oven.
Depending on the nature of the electric shock, the tissues involved can be heated to temperatures as
high as 5000◦C, thus converting the water content of the body cells and fluids to superheated steam. There
is progressive necrosis (death) and sloughing of the affected tissues. Damage is generally greater than that
inferred fromthe initial examination of the burned area. This situation occurs because the electric current
penetrates into the body, whereas thermal burns, such as those from contact with hot liquids or solid
surfaces, generally occur at the body surface. The heat produced by the passage of electric current through
biological tissues coagulates proteins, ruptures cells, and produces tissue death.When nerve and/ormuscle
tissues are involved, permanent effects may be expected that vary from partial impairment of function of
the limb(s) involved to complete paralysis.
Biological tissuesmay be modeled electrically as parallel resistance-capacitance circuits. ForDCand lowfrequency
AC currents, the resistive component controls the current levels produced by electric shocks. At
audio frequenciesandabove, capacitive reactancedecreases tovalues comparable tothe resistive component
of the tissue electrical impedance. This situation leads to the potential of very deep and searing burns when
electric shock currents pass through tissues. The effects of high-frequency current are put to beneficial use
in the now widely used electrosurgical apparatus (electrical scalpel). These instruments typically operate
in the 300–400 kHz range, and by modulating the wave form of the signal, surgical cutting, cauterizing,
or a combination of the two may be achieved.
GG,although you seem not to be affected ,do not try that ever again.
We love you ,man...
We need you .As,other people need you alive ,too I'm pretty sure ..
Take care ,man.
WTF ? Are you the dude from "jack-ass " who 's still alive ?
Cut the crap man,that's some serious shit ...
I like you being on that Earth,dude..
Do not act opposite,please..
Small favor,for me ?
Note : It's high frequency pulsed DC actually ...
(switching constant current power supply output )
But you never know..
Once ,shit will happen ...
No chance for "twice" ...
Not in this 'ride' ,at least ...
DO NOT TAKE RISKS.
Playing Russian Roulette with wires & pins ,FGS !!
Last edited:
Greengenes707
Well-Known Member
@stardustsailor
It was in the name of science! But totally understand you, and do very much appreciate the concern...and full education of exactly how stupid it was. I edited my post with a warning and hope no one attempts it themselves. And will not be purposefully touching them anymore. I like my dust in this form and in this current reality. So always good to know there is a certain level of safety imo with HV drivers. But always respect electricity.
You guys should know I am a field testing kind of guy by now...no matter the area of testing(plants, lights, rockets, soil, etc)... And did pretty much fully understand what I was possibly doing...though not as detailed as SDS just showed us.
At first I was very scared of the drivers. But then I had some issues with reds while using the 700 so I started pushing on the wires and slipped to a contact...no shock...so I got a little more comfortable and it just never zipped me so I tested around and nothing. The 1400ma's I am scared of because of the current. I touched them only a couple times and very quick/scared touches. I have very rough and calloused hands to my favor too.
I have Taser'erd my self with my girls taser...it's 900,000V...no idea on the amps....but it was 25$, shouldn't kill anyone right. Let me tell you it fucking hurts...but won't kill 99% of the time gauarenteed.
Anyways...yes I do some stupid shit every now and again...like men tend to do. And am young for all intents and purposes.
Oh ya and I smoke lots of pots...
Thank you again brother. Can't wait to see V-series in the hands of the creator. As well as other peoples Vero grows. I'll be watching till I join the V club...can you be a member more than one club?...haha JK.
It was in the name of science! But totally understand you, and do very much appreciate the concern...and full education of exactly how stupid it was. I edited my post with a warning and hope no one attempts it themselves. And will not be purposefully touching them anymore. I like my dust in this form and in this current reality. So always good to know there is a certain level of safety imo with HV drivers. But always respect electricity.
You guys should know I am a field testing kind of guy by now...no matter the area of testing(plants, lights, rockets, soil, etc)... And did pretty much fully understand what I was possibly doing...though not as detailed as SDS just showed us.
At first I was very scared of the drivers. But then I had some issues with reds while using the 700 so I started pushing on the wires and slipped to a contact...no shock...so I got a little more comfortable and it just never zipped me so I tested around and nothing. The 1400ma's I am scared of because of the current. I touched them only a couple times and very quick/scared touches. I have very rough and calloused hands to my favor too.
I have Taser'erd my self with my girls taser...it's 900,000V...no idea on the amps....but it was 25$, shouldn't kill anyone right. Let me tell you it fucking hurts...but won't kill 99% of the time gauarenteed.
Anyways...yes I do some stupid shit every now and again...like men tend to do. And am young for all intents and purposes.
Oh ya and I smoke lots of pots...
Thank you again brother. Can't wait to see V-series in the hands of the creator. As well as other peoples Vero grows. I'll be watching till I join the V club...can you be a member more than one club?...haha JK.
Last edited:
churchhaze
Well-Known Member
At a max of 143V, to calculate the resistance needed to get 1400mA draw, you'd use ohms law.
R = V/I
R = 143V/1.4A = 102ohm
That means the 5-10k resistance skin (or significantly lower if wet), won't even come to being low enough to drawing 1400mA at 143V.
That being said, it only takes 100mA through your vital organs to die, infact, there are studies that it's more likely to kil you at currents between 100-200mA than higher. (maybe more than just studies considering the defib units are based on that premise)
To get 1400mA through you at 5kohm resistance:
V = 1.4A * 5000ohm = 7000V
R = V/I
R = 143V/1.4A = 102ohm
That means the 5-10k resistance skin (or significantly lower if wet), won't even come to being low enough to drawing 1400mA at 143V.
That being said, it only takes 100mA through your vital organs to die, infact, there are studies that it's more likely to kil you at currents between 100-200mA than higher. (maybe more than just studies considering the defib units are based on that premise)
To get 1400mA through you at 5kohm resistance:
V = 1.4A * 5000ohm = 7000V
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SupraSPL
Well-Known Member
Yep, most likely the current was flowing through your skin but not enough for you to feel it. You can check with a multimeter. I was working on a lamp earlier and out of curiosity I checked the voltage difference between myself and the neutral leg of the 120V AC mains. There was about 3-4V but almost no current flow. If I had grabbed the hot leg, I would have felt the energy shooting up inside my arm and making my fingers tingle. It would be very interesting to see how much current would flow, but it is a very uncomfortable feeling so I don't think I am going to check LOL.
Anyway, it is very good to know that casual contact with the HLGs is not shocking DIYers
Anyway, it is very good to know that casual contact with the HLGs is not shocking DIYers
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ballist
Well-Known Member
I have been changing my mind between different veros. Looking at the vero 13 it looks to be the sweet spot for price, running. 16 (3500k)of those running at 700ma could work well. Now to find a driver with around 280Vdc at 700 mA. would use 8 per heatsink which should be just under 200watts and 20000lm approx.
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ballist
Well-Known Member
Thanks Supra, also found this one. A little on the pricey side though
http://www.digikey.nl/product-detail/en/LXD200-0700SW/633-1171-ND/2677294
I guess I will go for the meanwell option, 66€ on mouser
http://www.digikey.nl/product-detail/en/LXD200-0700SW/633-1171-ND/2677294
I guess I will go for the meanwell option, 66€ on mouser
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ballist
Well-Known Member
These are a good price for reflectors
http://eu.mouser.com/ProductDetail/Ledil/C13658_CLAMP-VERO13-18/?qs=sGAEpiMZZMurHQmwyojo5LwOASaLMSammSDbmKYEG%2bz2MXcDiRqf4A==
€1,66 in 1 offs
http://eu.mouser.com/ProductDetail/Ledil/C13658_CLAMP-VERO13-18/?qs=sGAEpiMZZMurHQmwyojo5LwOASaLMSammSDbmKYEG%2bz2MXcDiRqf4A==
€1,66 in 1 offs
ballist
Well-Known Member
Made by a different company and almost double the price. Meanwell are the go in higher power drivers it would seem.
Also the B version of the Meanwell is cheaper than the A
ballist
Well-Known Member
Yes very difficult, at just over €4,20 for the 10, €6,86 for the 13, €12,14 for the 18 and €27,79 for the 29. Todays prices from digi-key. I want around 300 - 400 watts in a 1sqm space
SupraSPL
Well-Known Member
That will make a hell of a nice flower room I spose the Vero29 has a slight edge over the rest, at least on paper, and it would be less labor to assemble it. The downside is it would need more vertical space and probably a reflector. The HLG-185H-C700 could run 8 of them, HLG-185H-C1050 could run 5, or the HLG-185H-C1400 could run 3, or 4 if you dim it a bit.
I spose the Vero29 has a slight edge over the rest, at least on paper, and it would be less labor to assemble it. The downside is it would need more vertical space and probably a reflector. The HLG-185H-C700 could run 8 of them, HLG-185H-C1050 could run 5, or the HLG-185H-C1400 could run 3, or 4 if you dim it a bit.
ballist
Well-Known Member
Vertical space should be ok as I get a tent with 2m of hight. From my previous tests with some China chips I do want reflectors and at 1,6 each it is no big cost increase. I do want the light well spread out and thats the reason I am thinking more along the lines of 13s or 18s. It's a little more work but I won't be drilling and tapping where I can avoid it. I would also like to add some 630 and 660 nm.
My idea is to build each light on a base of 300x600. 8 x vero 13 (3500k), 8 x 630nm and 8 x 660nm. I will probably place the reds on a separate driver for now.
I need to start a thread I guess
My idea is to build each light on a base of 300x600. 8 x vero 13 (3500k), 8 x 630nm and 8 x 660nm. I will probably place the reds on a separate driver for now.
I need to start a thread I guess
ballist
Well-Known Member
Ledil C13658_CLAMP-VERO13-18, with these
F13402_ANGELINA-W
F13661_ANGELINA-W-B
there is a link above but it might not work
http://www.digikey.nl/product-detail/en/CA11183_BROOKE-W/711-1083-ND/2354013
A lot of edits, I may try and mount 44mm ones from aliexpress as they are a lot cheaper and do work. Used them on multichips before.
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