I tried to make a longer title, but I kept getting the blank screen while trying to post my first post
A more appropriate title would be "Help with 555 idle current"
Can a moderator change?
Hello,
I need help to figure out how to keep the idle current draw at a minimum for this circuit. I built the attached 555 Schmitt trigger circuit on a breadboard.
http://www.allaboutcircuits.com/vol_6/chpt_8/2.html
However I substituted 2 relays for the 2 leds and then attached a motor so when the 555 sinks or sources the current it will energize the coil(s) and turn the motor. I also added a photo resistor next to the potentiometer to create a voltage divider going into the 555 so when it is dark the motor will turn one way and when it is light the motor will turn the other way.
In practice the motor will hit a limit switch to de-energize the coils - for now I just do that manually on the breadboard.
Ok so here is my question....
How can I have very little or no idle current draw when in "standby" mode?
The idle current draw of the circuit is around 2ma when using a semi depleted 9 volt battery. I plan on using 4 alkaline batteries 6V. So because of the current draw the batteries won't last long enough because of the 555 chip. I also tried the CMOS version, but it is about the same.
How do I get around this? Can I use another IC somehow, but it has to be able to energize the relay coils - I can't remember but probably aroundish 100ma.
Many thanks for any help you can provide,
Matt
A more appropriate title would be "Help with 555 idle current"
Can a moderator change?
Hello,
I need help to figure out how to keep the idle current draw at a minimum for this circuit. I built the attached 555 Schmitt trigger circuit on a breadboard.
http://www.allaboutcircuits.com/vol_6/chpt_8/2.html
However I substituted 2 relays for the 2 leds and then attached a motor so when the 555 sinks or sources the current it will energize the coil(s) and turn the motor. I also added a photo resistor next to the potentiometer to create a voltage divider going into the 555 so when it is dark the motor will turn one way and when it is light the motor will turn the other way.
In practice the motor will hit a limit switch to de-energize the coils - for now I just do that manually on the breadboard.
Ok so here is my question....
How can I have very little or no idle current draw when in "standby" mode?
The idle current draw of the circuit is around 2ma when using a semi depleted 9 volt battery. I plan on using 4 alkaline batteries 6V. So because of the current draw the batteries won't last long enough because of the 555 chip. I also tried the CMOS version, but it is about the same.
How do I get around this? Can I use another IC somehow, but it has to be able to energize the relay coils - I can't remember but probably aroundish 100ma.
Many thanks for any help you can provide,
Matt
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