Quote:
Originally Posted by Mike Dabrowski 2000
MR MIK
This document:
http://www.national.com/ds/LM/LM124.pdf
Page 9 Power Amplifier: shows how to use an NPN power transistor to drive high side big loads with an op amp.
Lamp driver page 10 shows a low side switch
Also you want to put a diode across the relay coil to prevent the inductive flyback pulse from blowing the transistor or op amp.
have fun, it is a very versatile circuit.
I sheared enough chassis to make 5 of the 350ma universal chargers, and 7 of the overnight chargers.
Also started setting up the microcontroller. |
Thanks again, Mike, I did indeed forget the diode...should have known that! But the LM324 seems to be fairly resilient, I must have turned the relay off hundreds of times (without a diode) while playing around with the hysteresis part of the circuit and experimenting.
Here is a schematic of how I plan to integrate it into the Special Freddy NHW10 EQ charger:
The trimpot R5 will probably be replaced with a fixed resistor in the final product.
More details here:
https://www.endless-sphere.com/forum...284578#p284578
Mik
