Hi, can anyone tell me how to go about extending the temperature range on the Velleman MK138 kit? I need to get it up to about 40 celcius, intending to use it for an incubator project. Go easy on me I’m not the sharpest tool in the box when it comes to electronics!
thanks
On the MK138 board itself it is indicated which resistors need to be changed in order to change the range.
Sorry, no values, please experiment.
Try this, I got it from a UK distributor, I’m going to make some alterations to the circuit first. I’ve seen a similar circuit, but it uses 16 x 110ohm resistors to generate the heat required. I think this may be a better solution to using a lamp as having a lamp switching on and off may confuse the chicks if I use the incubator as a brooder post hatching.
To increase the operating range of MK138 so it is suitable for use as an egg incubator thermostat (37.5º) with a hysteresis of approximately ±0.4º. Change the following components:-
Component Value Order Code
R4 4K7 1% 907-247
R5 3K9 5% 906-239
R6 2K7 5% 906-227
R7 10M 5% 906-610
RV1 1K 994-210
Brett