SURF PI TEMPERATURE PROBLEM

[daverave]

ive been experimenting with my surf pi circuit for the last few weeks and noticed when my room is cold and i switch on detector the depth proformance has decreased but if i leave it on for some mins and warms up then the detection depth works normal...is this a circuit problem or normal ???

[homefire]

I'm thinking Battery Issues.

[kt315]

too. 800mA*h sh-t.

[daverave]

i guess could be power supply...ive been using buck down voltage converter and sometimes a bit unstable...as threshold sometimes starts to pulse like beep beep a few times then settles down to steady audio...ive put a large capacitor on the output of buck to smooth out the switching noise but not sure what else i can do to get the buck converter more constantly stable.

[homefire]

Can you post a schematic of the converter ?

[daverave]

i have no schematic...its just a buck converter as sold on ebay from china.

[Polymer]

Hi daverave,

I just posted my thermal drift "experience" with the NUPI pinpointer.

http://www.geotech1.com/forums/showt...in-chain/page6

Post #555 - Hope this works, have never linked to another post before.

I wouldn't be surprised if it is temperature related.

Hope you get the problem nailed down faster than I did!

[daverave]

i have tried instead the buck up voltage converter and seems better than the buck down converter which may have been causing the problems...i put 15v input to get 16.5v out and the buck draw 50ma....and when input dropped to 12v the buck draw 130ma....and down to 9v input the current consumption 250ma....these converters very power hungry !!!! i may have to change from li-ion to duracell or energizer AA batteries but not sure the mah of these batteries ????

[daverave]

too. 800mA*h sh-t.

Hi kt...is that photo you when you were a boy or your son ????

[kt315]

hi,,, this is a boy from Stanley Kubrick's movie The Shining only an avatar...