Mk125 power source 12v car battery?

Kits Mini Kits Range
1

Hello

Im going to using the mk125 for our automatic door opener on the chicken coop.

Its all off grid so I was hoping to use a 12v car battery to power it. I see it requires a 12vdc power supply for the board and looking at the connections it looks like a laptop or phone charger type socket.

Can I hook it straight up to the car battery with an in line fuse or would this fry it or just not work?

Thanks for any help

Jonnym

2

Shoud work fine with a 12V car battery.
Make sure to put a fuse in the line, as you say.

3

Thanks for that.

I’m using it for an auto chicken door opener.

There are a couple of issues I’ve run into.

The adjustment doesn’t seem to work with the battery as I need to keep adjusting it. I’m guessing its because the battery is changing voltage and amperage as the battery discharges and charges. Which should I try to maintain the amps or voltage as constant, and could you suggest a way?

Is there away to adjust the delay so its longer? Sometimes on a cloudy day it causes the door to open and close.

Thanks for any help

Jon

4

Increasing C3 can help on cloudy days.
To avoid influence from battery voltage fluctuations, you could replace the relay with a 6V type and run the complete circuit from a 6V regulator (e.g. 7806).

5

Thanks so much for the reply, I’m sorry I missed it for so long.

I’m an electronics beginner, I’m guessing when you say increase C3, which is a 100µF, you mean get a higher µF number, could you suggest one? Even a 5 min delay would be fine by me.

I see the UA7806 velleman sell might fit the bill to stabilise the sensor, but I can find any info about what it looks like or how to use it. I’m going to buy it and have a play.

Thanks again for your help

Jon

6

Please experiment with the values for the cap (220µ, 330µ, 470µ,…)
As for the regulator, the 78xx datasheets shows some basics on how to use them.