Quote:
Originally Posted by Mike Dabrowski 2000
The insight PTC strip interface to the BCM has~ a 2.5K input impedance when the car is off, this parallel resistance will simply change the resistance slope as the PTC ramps up. That change in slope will not effect the ability to set an accurate shut down point. An op amp comparator can have better than 1 ohm accuracy, so I will simply tap the PTC plugged in, and go from there.
PTC strip auto charger shutdown circuit works well. Here is the schematic and photo of the bread boardcircuit.
two setpoints allow a warning and a shutdown setpoint. Total circuit should cost less than $5
MIMA Honda Insight Modified Integrated Motor Assist - PTC strip monitor and charger shutdown circuit |
OK, I'll try to understand how this part of it all works....
Hope you don't mind me asking a few questions, I'm a newbie to op-amps and have just figured out that the four "triangles" in the circuit diagram actually represent the same device - just showing it's various pins in four parts instead of in a single position.
That's how new I am to it all....
But why is there an electrolytic capacitor on the breadboard and not on the circuit diagram?
And is it correct to say that "upper setpoint", "PTC voltage" and "lower setpoint" are just labels to explain the circuit, rather than actual connections to components?
Now I'm off to find a spec sheet for the LM324 - need to figure out what it can do!
PS: How did you add hysteresis?
Mik
