jcdammeyer
Newbie
I'm using the standard resistors and diode to protect the external circuit from the PIC ICD2 12V programming voltage. A DS1813 external device pulls down the reset line whenever power drops below 4.65V.
The problem is 99% of the time the system sets perfectly but every once in a while as the main system power comes up, one of the peripherals driven by the rest appears to hang.
Power is supplied to the board as 28 to 36VDC. A switching regulator drops it to 12V and that is applied to a linear LM78M05 for the PIC and the peripherals. The way it comes up may well be the problem but before I dig further I'd like some feedback on the reset circuit.
Suggestions or comments?
John
The problem is 99% of the time the system sets perfectly but every once in a while as the main system power comes up, one of the peripherals driven by the rest appears to hang.
Power is supplied to the board as 28 to 36VDC. A switching regulator drops it to 12V and that is applied to a linear LM78M05 for the PIC and the peripherals. The way it comes up may well be the problem but before I dig further I'd like some feedback on the reset circuit.
Suggestions or comments?
John
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