power on reset circuits

AnalogKid

Joined Aug 1, 2013
12,205
Lower right corner, D7 needs a current limiting resistor from anode to +12V
Same circuit area, what are the two parallel rows of three dots?
What are the two voltage rails st the top right corner?

It looks like Q1 and Q4 charge and discharge C3,4,5 in switched combinations, but there is no series impedance to create timing differences. What is the intent of the overall circuit?

AND, of course, you can do everything in a PIC.

ak
 

dl324

Joined Mar 30, 2015
18,432
Aside from having no connection to Set I don't see any problems with how the CD4013 are being used.

Why are you using an inverter on the Q output instead of simply using the Q# output?
 

Thread Starter

shortbus

Joined Sep 30, 2009
10,049
Thanks guys. This was a first attempt from a year or two ago. I got way laid with life and kind of gave up because people told me my idea of the "T" style flip flop was not going to work. I'm going to try again to get it more refined.
I know just enough about this stuff to be dangerous.

Same circuit area, what are the two parallel rows of three dots?
Those are there to represent the spark gap, between the electrode and the metal being cut.

AND, of course, you can do everything in a PIC.
Two problems with using a PIC. (1) the circuit is very noisy due to the spark gap @ ~100V. Some others have tried and the gave up because of the noise. (2) I'm having a hard enough time learning electronics, no need to learn programing too. :)

Why are you using an inverter on the Q output instead of simply using the Q# output?
I knew I would need some kind of inverter for the power on part of this, so just used the extra inverter's since there are 6 on the chip. And thought it would help reduce any shoot through problems from the low side mosfets. They are only there to charge the boot strap caps for the high side mosfets.
 

Thread Starter

shortbus

Joined Sep 30, 2009
10,049
I missed that. I too see everyone suggesting that and ask myself why. Though I'm still a learner. But my answer was from what others trying to do this have claimed. The industrial machines do use computers, but don't know what they do to get around the 'noise'.
 
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