#1608 NE556 one 555 gates a second 555

Episode 1608
How to trigger on this waveform

[rockpadstudios]

I was in a HP demo and the guy laughed that the auto button was only use by software types. Real engineers know what buttons to push. Well he was showing us a battery monitor unit and things got complicated and he smiled and said "I hate to say this but I have to press the auto button". That was worth going to that demo. :)

[HeyBirt]

In the mid 1980s I went to vocational school my last 2 years of high school to study electronics. One after noon I set a 556 up to produce a short pulse about one a minute which gated the second timer which produced an audible tone through a small buzzer. A 9V battery was connected and I snuck across the hall and taped it under the nurse's desk (who was also the wife of my instructor).

About 20 minutes later in she walked with the device in hand. She walked directly to me and said, 'You can have this back!" I still don't know how she knew it was me :)

[Captain_Adam]

Helpful guidance on the duration based triggering. Thank you!

[rahulkushwaha]

Thanks for sharing that triggering trick in the end. Couple of days back I was struggling to see the PWM signals from a microcontroller to the BLDC motor controller. As the duty was changing oscilloscope struggled to trigger in edges for some reason. I will try this method to see the waveforms. Thanks

[billywallace]

A fun example to use both sides of the 556 is Forrest Mims's Atari Punk Console.

[DiaconescuAlexandru]

I did a very similar thing but with CD4093's as astable oscillators, one side of the NAND gate was hooked up to a binary counter which enabled/disabled the astable. I had four NAND gates setup like this and made some nice tunes with them and a audio mixer 😄

[jp]

Digital scopes are cool. All the trigger options is insane. Many don't make any sense.

[TeddehSpaghetti]

This is basically the guts of the Atari Punk Console DIY synthesizer?

[Electronzap]

Nice. I wish they include the 556 in assorted IC kits that include the 555.

[romancharak]

I don't understand where that circuit would be useful. Could someone please explain?

[opera]

I hate the 555. I was around when they first came out and they had issues. Never got over that. They are fine for learning some electronics, for blinking a light or windshield wiper delay. You can make anything with them but it probably won't be very good and it will need a lot of parts. There are so many chips that will do the job much better. When I see a circuit with a 555 I will ignore it because they probably aren't a real designer and there are probably other issues in the circuit.

[nickcaruso]

i have heard that there are an amazing number of circuits based on the 555. is there a good compendium of examples, either in print or online?

[markhumes]

I have that same scope. Does yours make an annoying clicking noise when acquiring?

[ohaya]

How do I pronounce the IMSAI in your channel name? 😊