Inside a TM623 astronomical time switch.

In hindsight I should have explored the module more. I was more interested in the power and switching circuitry at the time.

Big Clive

The surface mount resistor and unpopulated capacitor seems to be an optional extra layer of filtering on the battery/module charge supply. Possibly in case the coil switching crashed the control module.

Big Clive

You're right. If I'd thought of it at the time I could have changed the date to see how the on and off times changed.

Big Clive

You forgot to show us how to set the astronomical function part of the timer. I bought one of these from a well known US manufacturer a few years back. It is unbelievably hard to set up. You have to sit down with the instructions (and my cheat sheet). Cannot make any change to the setting without it getting messed up,, you have to reset and start from scratch every time. The charging circuit never worked, once the battery exhausted, every little power outage would cause it to lose programming. I thought it just a failed battery at first and wired in an old cellphone battery, which worked about a year. Finally realized what was going on and wired in a 18650 which I take out every 6 months and charge. Electricians around here will not install them anymore unless the customer takes full responsibility for setting them.

Paul Malloy

Thanks for this instructable (de-structable) video Clive. I have had one of these for a while now for turning off the auto iris lenses of my CCTV meteor cameras to protect the CCD from sunlight when not in use. (Our group would benefit from this video when you release it (nemetode.org). I have struggled to understand the poor instructions and it has been left on my shelf forgotten, so this is appreciated. Mine is badged up as a HNG NKG-3 but is virtually the same. I opened it out of interest and noted there was no MOV (no Ident, not drilled) C2 looks smaller 6.3mm, the value is 100uF 50V though. Underneath it there is a ident C9 (not populated) but gives a bit of space from D5. Ther is also a SMD footprint on the solder-side marked R7 (not populated. I'll get this working finally now!

That relay looks like a fake Omron

Michael Thompson

Somewhere out in China An engineer is getting stoned again... Well it's 5:30 in the morning Watching Big Clive tear it down my friend. He said it's 1o'clock in the morning and he's just now tapped on SHIFT again. Big Clive playing with a timer Big Clive playing with a timer son Big Clive playing with a timaaaah Big Clive playing with a timer hon

Michael Thompson

Thanks for the video. Please keep on 'fiddling about' in your videos, it makes them very interesting to watch (for me).

Paul Schuur

Whats the name of the main MCU on the LCD board?

Western Canadian Guy

We have a similar one in or workplace and it its a pain in the butt to get it programmed. And it was also very expensive. Around 70 euros

Looks like a Holtek MCU. They make LCD drivers and 8 bitters and more recently, ARMs.

Mike Page

Nice. Thanks.

Bas