Print PDF
Favorite
Email
Step 3Assembly
Assemble the 1k resistor, diode, and 100uF capacitor on a terminal strip or perfboard. The purpose of this circuit is to convert the output of the thermostat, which is AC, into a DC signal to drive the relay. There is a fair amount of flexibility in this circuit - these are just parts I had in my junkbox.
The thermostat uses a triac to switch the heater on and off. Triacs only work with AC signals, they can't be used directly to switch DC because they will "latch" on and not turn off until power is removed. The 1k resistor in the circuit ensures that a small amount of AC current can pass through the triac and avoids the latching problem.
The thermostat uses a triac to switch the heater on and off. Triacs only work with AC signals, they can't be used directly to switch DC because they will "latch" on and not turn off until power is removed. The 1k resistor in the circuit ensures that a small amount of AC current can pass through the triac and avoids the latching problem.
| « Previous Step | Download PDFView All Steps | Next Step » |
 |
Add Comment
|
