BrillTheStudent
Member
Fire Safety Project.
Here's a short write up on an inexpensive way to add some additional autonomous fire safety gear to your grow room.
Start with a cheap smoke detector; the Universal brand Model SS-770. Available in many home improvement stores and Walmart. Cheaply available online for those who can't find a local source. This smoke detector, and probably many like it, has a handy feature built into the board.
Take smoke detector apart. It's held together with three locking tabs. They are tight, but it can be done with a screwdriver.
Take the board out. Take the white plastic piece off, again held in with clips. This is the speaker leave it out if you don't want the detector to sound.
What? A smoke detector that doesn't sound? What's the point in that? Well, I'll tell you. We're going to use the predrilled and labeled ports on the board to make our smoke detector actually *DO* something in response to smoke. For the purposes of our example, it will be to kill the lights but it could do anything you want, say open the solenoid valve on your CO2 tank to flood the room with fire killing CO2.
See the hole labeled I/O? This is our logic output. It's signaled high for smoke alert; low normally.
These boards probably can't handle much current, so I'm going to add an inexpensive transistor to allow the detector to directly fire control relays.
For this, I used a TIP31A transistor [available at any radio shack], and a 470 ohm resistor. The resistor goes in R10, the transistor legs go as shown. [NOTE: You can use any general purpose NPN switching transistor here. But, look at your transistors pinout the three legs a labeled: E-Emitter, B-Base, C-Collector. The Emitter MUST go to ground, and the base MUST go to the resistor. No exceptions.] Connect some wire to the remaining leg of the transistor, and to the other ground hole. These are the wires you'll use in the control circuits.
A note on soldering: it's not hard, and you don't need fancy equipment. The $10 soldering iron in the automotive section of walmart works fine, and comes with a roll of solder.
Reassemble.
Now, you have a smoke detector with a piece of cable coming from it. If smoke is detected, the detector will let electricity flow through this cable, IN ONE DIRECTION.
[More to come, how to wire an inexpensive HVAC control contractor to safely run your lights, kill them in the event of smoke, and as an added bonus, disallow them to automatically try to restart in the event of a power blip. That is, avoiding hot restart. Useful for those of us on magnetic ballasts!]
Here's a short write up on an inexpensive way to add some additional autonomous fire safety gear to your grow room.
Start with a cheap smoke detector; the Universal brand Model SS-770. Available in many home improvement stores and Walmart. Cheaply available online for those who can't find a local source. This smoke detector, and probably many like it, has a handy feature built into the board.
Take smoke detector apart. It's held together with three locking tabs. They are tight, but it can be done with a screwdriver.
Take the board out. Take the white plastic piece off, again held in with clips. This is the speaker leave it out if you don't want the detector to sound.
What? A smoke detector that doesn't sound? What's the point in that? Well, I'll tell you. We're going to use the predrilled and labeled ports on the board to make our smoke detector actually *DO* something in response to smoke. For the purposes of our example, it will be to kill the lights but it could do anything you want, say open the solenoid valve on your CO2 tank to flood the room with fire killing CO2.
See the hole labeled I/O? This is our logic output. It's signaled high for smoke alert; low normally.
These boards probably can't handle much current, so I'm going to add an inexpensive transistor to allow the detector to directly fire control relays.
For this, I used a TIP31A transistor [available at any radio shack], and a 470 ohm resistor. The resistor goes in R10, the transistor legs go as shown. [NOTE: You can use any general purpose NPN switching transistor here. But, look at your transistors pinout the three legs a labeled: E-Emitter, B-Base, C-Collector. The Emitter MUST go to ground, and the base MUST go to the resistor. No exceptions.] Connect some wire to the remaining leg of the transistor, and to the other ground hole. These are the wires you'll use in the control circuits.
A note on soldering: it's not hard, and you don't need fancy equipment. The $10 soldering iron in the automotive section of walmart works fine, and comes with a roll of solder.
Reassemble.
Now, you have a smoke detector with a piece of cable coming from it. If smoke is detected, the detector will let electricity flow through this cable, IN ONE DIRECTION.
[More to come, how to wire an inexpensive HVAC control contractor to safely run your lights, kill them in the event of smoke, and as an added bonus, disallow them to automatically try to restart in the event of a power blip. That is, avoiding hot restart. Useful for those of us on magnetic ballasts!]