Energy regulation circuit - help please

Hi,

I have a project in mind that requires the switching on & off of a domestic refrigerator. The purpose is to control the internal fridge temperature at a level suitable for brewing lager beer. The highest setting available on fridges is of course too low & would stop fermentation.

My idea is to provide an adjustable (timer controlled?) circuit that would operate a relay & allow switching "on" for say 30mins & then "off " for say

60 mins. This should allow the desired temperature of 18 to 20 Deg C to be achieved with a little trial & error.

Can anyone oblige by helping me with a simple circuit preferably made from easily purchased low cost components.

Thanks Pete

Reply to
peterlonz
Loading thread data ...

You could probably do this with a regular air conditioner thermostat and a relay. Put the 'stat in the fridge and feed the fridge power through the relay.

Alternately you can make a pretty good thermostat with a thermister and a whetstone bridge, feeding a 741 Op Amp, picking a relay.

Reply to
gfretwell

If you find the thermostat in the fridge, it will likely have a course adjustment screw on it, which you can turn to make the thermostat operate over a completely different temperature range. A bit of trial an error will be required to set it. If it's electronic, a trimmer adjustment or resistor change might achieve the same thing.

Reply to
Andrew Gabriel

look for a "ice cube" timing relay. You will need to find one that is motor/current rated for your application, compressors on start up are 6 times the running amps.

formatting link
check Automation Direct, or Potter Brumfeild

Reply to
SQLit

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.