Help with simple timer circuit

Thread Starter

Bikerman

Joined Feb 19, 2020
2
Hi,
I'm a systems manager by trade and my knowledge of electronics is slight. I can handle a soldering iron and know a capacitor from a resistor but otherwise I'm pretty clueless.
Here's my problem....
I'm currently trying to construct a mobile/artwork which involves dangling the mobile on a chain, from the ceiling. In order to work, the chain needs to be spun and then stopped. The amount of time spinning is probably around a second or two and the amount of time stopped needs to be variable between a few seconds and a minute or so. So it is REPEAT: on for a second, off for 5<x<60 seconds: FOREVER.
I have a 3V geared-down tiny electric motor which will do the spinning. What I need is a simple circuit which can interrupt the power to the motor after 1-2 seconds a keep it down for a variable time (say 5secs to 1min), before repeating the cycle. I plan to power it from 2x1.5V batteries - though I might adapt it to use a 3V transformer from mains later.
I sort of think that I'm going to need a relay and a timing circuit (555?). But I'm not competent to design the actual circuit...
Any help gratefully received........and I promise to post pictures of the completed project :)Best wishes
Chris.
 

AlbertHall

Joined Jun 4, 2014
9,331
Those suggestions won't work on the 3V desired by TS.
For battery operation I would suggest a LMC555 and a MOSFET to switch the power to the motor.
 

eetech00

Joined Jun 8, 2013
1,838
Hello,

Here is a timing circuit using a TLC555 (Similar to LMC555 CMOS as mentioned in post #4).
On time is fixed at ~1 second. P1 is a 1 Megaohm adjustable potentiometer. When potentiometer is at full rotation, off time is ~64 seconds max, and at minimum rotation, off time is ~5 seconds.

eT

See below.

1582169572345.png
 
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