Electrically Simulate Pressing a Momentary Switch Every 30 Seconds

Thread Starter

buzzlebeebizzle

Joined Dec 12, 2025
24
All,

Thank you each for helping me sort this out!

I believe I'll go with the TLC555 solution, as it seems to do what I need it to do in a simple, efficient, and inexpensive manner.

You all are amazing!

PS: Once I get this done, I'll report back with results.

buzz
 

Thread Starter

buzzlebeebizzle

Joined Dec 12, 2025
24
Also, I'd like to order those 1uF caps at Digikey while I'm ordering the TLC555s.

There are too many options there for me to sort. Would someone recommend one in particular?

Amazon might be a better bet. Is 50V 1uF okay?

Thank you!
 
Last edited:

MisterBill2

Joined Jan 23, 2018
27,530
You only mentions three leads.

You need to connect Pin 14 to your 4.5 V DC and Pin 7 to your GND (the negative side of your battery pack).

Any unused control pins (pins 5,6,12,13) need to be tied to GND or Vdd. The easiest way to do this is choose either pin 6 or pin 13 as your unused switch and tie it to the power pin right next to it.
In the CRUTSCHOW circuit in post #11 THERE ARE NO UNUSED CONTROL PINS !!!!! Every bit of the IC is used!
 

WBahn

Joined Mar 31, 2012
32,852
In the CRUTSCHOW circuit in post #11 THERE ARE NO UNUSED CONTROL PINS !!!!! Every bit of the IC is used!
Here's his circuit from post #11:

1765833813589.png

I see three switches.

I always thought that the reason that the 4066 was called a "quad bilateral switch" was because it contained four switches.

1765833952176.png

If it uses all of the switches, why does he say "Connect unused U1 input to ground"?
 

sarahMCML

Joined May 11, 2019
697
@sarahMCML: I'm confused on a couple of points in your layout.

1) What is the significance of the circles like these?

View attachment 360599

2) The drawing implies that board consists of horizontal tracks from side to side (such that the IC pin 11 is connected to R3 and R4 and also to a wire that goes down to C1). But, if that's the case, then wouldn't both C1 and C2 be shorted out? And wouldn't opposite pins on the IC be shorted together?

Are the circles places where the tracks have been cut?

But even that would still leave a number of things shorted, it would seem.
Correct, the circles are places where the tracks are cut.
I failed to notice that the track cuts horizontally between the two pins of each capacitor haven't been brought to the front, and so don't show on the image! Poor checking on my part!
Pins 1, 2, 13 and 14 all connect to Vcc (strictly Vdd for CMOS!), so no tracks are cut under the I.C.
 

MisterBill2

Joined Jan 23, 2018
27,530
Here's his circuit from post #11:

View attachment 360614

I see three switches.

I always thought that the reason that the 4066 was called a "quad bilateral switch" was because it contained four switches.

View attachment 360616

If it uses all of the switches, why does he say "Connect unused U1 input to ground"?
Consider that the remaining section is what would be used to provide the switching function across the triggered device push button. When evaluating a circuit it is useful to consider the actual application, not just what is shown. So while that fourth switch is not part of the oscillator circuit, it is certainly part of the application.
 

WBahn

Joined Mar 31, 2012
32,852
Consider that the remaining section is what would be used to provide the switching function across the triggered device push button. When evaluating a circuit it is useful to consider the actual application, not just what is shown. So while that fourth switch is not part of the oscillator circuit, it is certainly part of the application.
So... what is the far right switch used for? You know, the one whose switch contacts are labeled "PB", as in "Push Button"?

When evaluating a circuit, it is also useful to actually consider what is shown, not just the application.
 
Last edited:

BobTPH

Joined Jun 5, 2013
11,516
Cool little project. Since the built‑in IC is non‑retriggerable, that CD4066 + multivibrator idea really is a neat way to “tap” the button electronically at a fixed interval without having to hack the logic itself. For a first build, I’d probably copy crutschow’s perf‑board layout as closely as possible and keep all wiring short and neat so it actually fits inside the snowman’s base.
Why would he do that when he already has a working circuit? And one simpler for him to understand and build.
 

ulms

Joined Mar 19, 2024
179
I have a small snowman with lights that sits on the mantel. It takes 3 x 1.5V AA batteries.

It has a momentary switch, and when you press the momentary switch, the snowman lights up in various places and in sequences.

After 30 seconds the lights return to off.

I want the lights to stay on indefinitely (until I turn the on/off switch off).

I held the momentary switch to see if the lights would stay on, but even holding down the momentary switch, the lights turn off after 30 seconds of activity.

I'm looking for an easy way to electrically simulate pressing the momentary switch every 30 seconds to keep the lights on until I turn the power switch to OFF. Or to bypass the momentary switch altogether, although I believe the IC is controlling the lights,so this may not be possible.

What is the simplest way to do this?

Thank you,

buzz
Be careful what you wish for!
 
Top