How's my growbox? What should I add?

kimoolos

kimoolos

Well-Known Member
Right on right on! That's more than enough light for a baby seedling. You can start with just a few of the 23w since she's so small and work your way up as she gets bigger. That'll give you time anyway to figure out the temp issues as you add more lights. Play with your light height. Do the back of the hand test, see how she responds. If she starts stretching move em closer, if she starts curling or leaves start looking like football uprights back the lights off. I usually have one 43w cfl maybe even 2" off the top with no issues, but I tested first.
 
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TheDrewdogg

Member
Thanks for all the help guys, I appreciate it. :)

This morning I was shocked to find my temps had swung abot 20 degrees, from 61 to 84 total.
Seeds are still germing so I'm not too worried but time is running out for me to have issues like that. I altered my light cycle to night on day off, 18-6, (f*** my landlord) and backed off my ac while increasing fan voltage back to 12v, but I think I'm about ready to drop a couple bucks on some method of automating temperature control. Has anyone ever cut up a thermostat? I need something to kick on the AC only when it's too hot and shut off the ac when it's within range, and shut off the fans when it's too cold and turn them back on within range. Would a cheap AC thermostat handle it or should I build the circuit from scratch (please no, I'm lazy, a stoner, and in college.)
 
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TheDrewdogg

Member
Update: I bought a cheap manual thermostat to gut. Basic manual honeywell piece, ~$20 at home depot. Also a relay from a car, 5 prong with on and off options (I used a black nissan relay)

Only need one piece, the piece with the thermostat, not its control board. Hook power 12v+ to the center electrode, fans to cool side, and AC cutoff is fed through the relay on the heat side. Theory is, if it gets too hot, the fans kick on to drop the temp (bringing in more AC'd air, which is always blowing into the box cuz the AC fan pushes it in), and if it's too cold the AC will kick off to bring it back up. I'll upload pics of the concoction if it works.
 
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TheDrewdogg

Member
So here's how it works.
The thermostat is a coil that moves according to temperature. It's attached to an arm that arcs between two contacts, and adding a current to this device allows to two contacts to actsact as bridges. Due to the design, the tighter side of the coil will pull towards the inner contact and bridge only when the temperature is below a set point. Heat it up, it expands to touch the outer. So you adjust the set point and you adjust the desired temperature.

I ran 12v+ through the coil. Hooked the fan positive to both sides, and a wire to the coil of a relay on the hot side.
This relay is cutting off the main line for the AC's AC. Uhh. I mean the air conditioners electrical supply. Cut one wire and bridge to relay switch. Set for normally open, and ground the circuit to the supply. Placed the thermostat inside the cab and crank up the AC.

Idk how well it works but it's cheap and should at least keep my plants alive.
Last night the box hit 100 degrees while I was out. Can't let that happen. Also, I'M A GANJA DADDY NOW. :')
 
SPLFreak808

SPLFreak808

Well-Known Member
TheDrewdogg said:
So here's how it works.
The thermostat is a coil that moves according to temperature. It's attached to an arm that arcs between two contacts, and adding a current to this device allows to two contacts to actsact as bridges. Due to the design, the tighter side of the coil will pull towards the inner contact and bridge only when the temperature is below a set point. Heat it up, it expands to touch the outer. So you adjust the set point and you adjust the desired temperature.

I ran 12v+ through the coil. Hooked the fan positive to both sides, and a wire to the coil of a relay on the hot side.
This relay is cutting off the main line for the AC's AC. Uhh. I mean the air conditioners electrical supply. Cut one wire and bridge to relay switch. Set for normally open, and ground the circuit to the supply. Placed the thermostat inside the cab and crank up the AC.

Idk how well it works but it's cheap and should at least keep my plants alive.
Last night the box hit 100 degrees while I was out. Can't let that happen. Also, I'M A GANJA DADDY NOW. :')
Click to expand...
Did you say you have a 12v 40a spdt relay cutting 120vac from the air conditioner on prongs 30 and 87?
 
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TheDrewdogg

Member
After finished testing, yes, I do indeed have a DC relay rated for upwards of 40A handling a 15A 110v load, and there's no heat concerns. The AC, the socket, and the relay's power supply have protection circuitry, and it seems to handle it just fine.

But yes, not exactly "safe", I know. Dunno what you mean about prongs, it's on prongs 3 and 5.
 
SPLFreak808

SPLFreak808

Well-Known Member
TheDrewdogg said:
After finished testing, yes, I do indeed have a DC relay rated for upwards of 40A handling a 15A 110v load, and there's no heat concerns. The AC, the socket, and the relay's power supply have protection circuitry, and it seems to handle it just fine.

But yes, not exactly "safe", I know. Dunno what you mean about prongs, it's on prongs 3 and 5.
Click to expand...
Be careful. An ultra high quality bosch relay can only handle 450w burst 300w continuous at 12v (2.6-3a 120v) I use relays daily, sorry i label them by the actual pin numbers. They do sell SPDT relays with bridge contacts that are rated for 120v AC and can be triggered by 12v. A car relay however is made for DC, they did not design it to protect itself from any field created by alternating current through the coil. 120v AC can still pass through contacts thay are close but not touching. Put a 1amp fuse to the 12v positive and negative trigger could save you're 12v supply incase of relay failure. Hell it could even save you're house from burning down smelling like MJ at the same time. The protection features only protect internal faults/shorts. It may not protect 120v being fed into it because they do not think anyone would do that.
 
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TheDrewdogg

Member
Okay, I'll attach a couple fuses to the system too, sounds like a good idea. Not too worried about the supply cuz I gutted it from a goodwill pc, but a house fire is a good thing to avoid. Glad there's an electrical guru on here to correct my mistake.
 
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