Good quality and weather proof temperature probe supplied with 2 meter long tough cable, and mounting clip. Suitable to interface with popular microcomputer such as PIC's and others. 100% compatible with all Solafriend control boards.

£25.00 each plus £2.00 postage and packing.


See it on Youtube here

Solarfriend # 1. Discontinued no longer for sale.

Uses Pic 16F676 Microcomputer.

Needs a 7 to 15 volt supply and two temperature probes for a minimal no frills system. Three controls.

Control 1 = Diff. Switches on the relay when panel probe is hotter than tank probe by the temperature difference of this control 0 to 25 degrees C approx.

Control 2 = On time. Relay closes for a time 0 to 25 seconds this control.

Control 3 = Off time. Relay opens for a time 0 to 25 seconds adjustable. by this control.

Relay has three terminals. Normally open: Common: Normally closed: And can handle 3 amps at 24 volts DC. Connection to mains not recommended.

Relay on light and Too cold light that flashes every 10 minutes when shut down.

Current consumption is about 2 ma when running and about 50 ma when relay energized.

In a typical bare bones system this board will run from a rechargeable battery that is kept charged by a P/V panel. The temp probes would be on the panel and on the tank. You adjust the relay on off times to suit your pump and system. Typically 5 seconds on and 15 seconds off.

Shuts down and idles if panel temp probe is below 10C. Starts up again if panel temp probe goes above 10C.

On board trimmers can easily be replaced with 100k linear potentiometers fitted to control panel.

£30.00 each plus £2.00 post and packing .

See it on Youtube here

Solarfriend # 3 A complete solution for most DIY set ups. Independant control of difference temperature, on time and off time. Low battery indicator. Too cold indicator. Pump on indicator. LCD display shows. Battery voltage. Panel temperature. Tank temperature. Difference temperature. On time. Off time. Also has AUTO mode that sets difference mode to 10C. And runs pump on a variable rate depending on panel temp. Shuts down if battery fails or panel temp is below about 18C.


Solarfriend # 3 including two probes £99.00 inc UK postage and packing.

Overseas customers please add £15.00 for postage

Postal costs outside UK are now getting significant please email me before ordering

Postage to Ireland and USA for example has doubled the last couple of years.

30-08-13 Had to put the UK price up today due to spiralling postage costs.

Postage to non UK destinations now £15 due to constant postal increases.