by windgat on Wed Dec 02, 2009 11:03 pm
Once the circuit is assembled, follow these steps to set it up
1. Measure these two voltages:
- Battery input (pin 1 of incoming wire connector), e.g. 25V
- Between R1 and R2, e.g. 2.47V
Now divide the first by the second e.g. 25/2.47 = 10.121
2. Choose the voltage at which you want to start dumping, say 28.5V
Divide by the above factor, e.g. 28.5/10.121 = 2.82V
Turn the pot P4 until the voltage at the test point next to it reads this voltage
3. Now choose the voltage at which you want to stop dumping, say 27.9V
Divide by the above factor, e.g. 27.9/10.121 = 2.76V
Turn the pot P3 until the voltage at the test point next to it reads this voltage
4. Now choose the voltage at which you want to turn off the load, say 23.5V
Divide by the above factor, e.g. 23.5/10.121 = 2.32V
Turn the pot P1 until the voltage at the test point next to it reads this voltage
5. Now choose the voltage at which you want to turn the loads back on, say 25V
Divide by the above factor, e.g. 25/10.121 = 2.47V
Turn the pot P2 until the voltage at the test point next to it reads this voltage
Then it should be ready to go!
If you have access to a variable voltage power supply, you can verify the circuit is working as follows:
1. Connect the voltage supply, and dial up the voltage to 29V.
2. Measure output A - it should be high (6V).
3. Now slowly turn down the voltage, and as it passes 27.9V output A should go low (0V).
4. Check output B - it should be high.
5. Turn down the voltage slowly to 23.5V, and as it passes 23.5V, output B should go low.
6. Turn the voltage up again slowly, and as it passes 25V output B should go high again.