Re: RESET circuit tweaks
Posted: 10 Nov 2018 20:04
So by my calculation thats 480uF assuming those numbers are uF.
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So by my calculation thats 480uF assuming those numbers are uF.
No double cap here. Its a 10 ufIcky wrote: 10 Nov 2018 19:58Thanks Forgottenmyname - I notice your C3 is two caps in parallel. What value are they?Forgottenmyname wrote: 10 Nov 2018 19:51 If it helps, here's a photo of my Mega reset circuit, in case something is a different value to the schematic.
20181110_194921.jpg
And now its gone back to the occasional bouncing inverted reset out after powering on again.Icky wrote: 10 Nov 2018 20:14 Just tried 470uF in parallel.
Its weird. Its just doesn't seem to be behaving as expected. Reset switch doesn't affect anything. Have checked and checked the circuit. I have two TL7705's so both of them cant be duff.
Interesting spot. I just powered on the prototype circuit again and it seemed to work with pulses.Forgottenmyname wrote: 10 Nov 2018 20:27 Being thick today but comparing schematics, mega values for C1 and C is .1uf but we are using 10nf.
Also bizarrely, the data sheet for the 7705 shows ref connected to VCC but on the mega drawing and the reset board it goes to gnd via a cap.
data sheet if useful
http://www.ti.com/lit/ds/symlink/tl7705b.pdf
And now its back to no activity on inverted Reset. :headbang:Icky wrote: 10 Nov 2018 20:30Interesting spot. I just powered on the prototype circuit again and it seemed to work with pulses.Forgottenmyname wrote: 10 Nov 2018 20:27 Being thick today but comparing schematics, mega values for C1 and C is .1uf but we are using 10nf.
Also bizarrely, the data sheet for the 7705 shows ref connected to VCC but on the mega drawing and the reset board it goes to gnd via a cap.
data sheet if useful
http://www.ti.com/lit/ds/symlink/tl7705b.pdf
Screen Shot 2018-11-10 at 20.27.15.png