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Clean square waves using a 555 timer?

barjammar

May 12, 2018
1
Joined
May 12, 2018
Messages
1
Hi I just joined the forum. I noticed the same glitch on my Rigol 1104 'scope. The circuit was very similar - Ben Eater's "clock" circuit on his breadboard computer (https://eater.net/bbcpu8-clock-module/). I found the discussion here interesting but the answers unsatisfying. I think I like the inductance theory and would try blocking the spike if its coming in on the power supply. I'll let you know (it is two years later now!) what I find out. I've attached the picture of the circuit from Ben's YouTube video of the clock part 1.
I will post the glitch when I get back to that location but, since it looks identical to the one discussed here, I think it is independent of the wiring, load (an LED here) and exact layout.
ben eater clock circuit.jpg
 

Audioguru

Sep 24, 2016
3,656
Joined
Sep 24, 2016
Messages
3,656
Get rid of the solderless breadboard with capacitance between its many rows of contacts and tangled long wires all over the place. Each wire has series inductance. The intermittent contacts are not designed to handle the 400mA shoot-through current of an ordinary 555 and a 9V battery also cannot handle 400mA current spikes.
 
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