A timer device with relay

A number of Intermatic timers run on a battery, but control a relay that can be controlling any voltage up to 220VAC. ...Jim Thompson

What's low power? AC, DC what voltage? Something like an AC synchronous clock motor and gear head that spins once an hour?

George H.

A simple 55IC timer will do you. Google on 555 timer circuit. It's simple IC plus a few resistors and caps. The 555 output will need to drive a transistor base thru a ~5K resistor to pull in the relay between the collector and power supply.

Does it need absolute accuracy (a specific time of day) or relative accuracy (every X hours +/- x minutes)?

Picaxe is easy to use and can be happy on a few micro amps. 555 (cmos version) ditto. Picaxe can be set from milliseconds to decades without large timing caps.

I'm doing stuff with small solar cells and capacitors for power storage.

If the arduino's using too much current you're doing it wrong.

The old favorite ne555 will be suggested by many, but it does draw 1 - 5 mA while doing nothing. Much lower power use can be obtained from something like a Texas Instruments MSP430 MCU running Mecrisp Forth in low power mode 3

The Ti datasheet indicates that a maximum quiescent current draw of 1.5 uA applies in LPM3 (low power mode 3) with a 32768 Hz clock.

Of course the MSP430 MCU can be used for a lot more than crystal controlled timing delays at the price of more power usage.

Cheers, Terry

You can use a RTC, like:

and program it to set the Square Wave Output every hour.

Bye Jack

Vampire voltage?

the internal voltage divider

Test wrote on 10/25/2017 9:00 AM:

Is this what you are looking for?

rickman wrote on 10/27/2017 7:12 PM:

If 15 mA is too much current, you can use this with a low power MCU board.

Here is a low power MCU board.