I have a fan on top of the heat sink and want to control it with the accy connector. I know X7 (pin 3) can be used to turn on the fan based on the settings in eSDR. This is a 12V Fan. Do I connect to pin 14 and let it run on 5V? Is pin 3 then just closing the ground?

Yes, you can use +5V(pin14) and X7(pin3) for control 12V fan. It will rotate with less speed and it's enough for cooling the transceiver.
If you want to use external power source for fan, you have to connect +U to first pin of fan, second pin of fan to X7, -U of power source to pin 15 GND.

Hi All,

What are the colors of the cooler?

Red = 5V EXT CTRL = + 5V
Yellow = 12V EXT CTRL = X7
Black = Minus (-) EXT CTRL = G

Is this correct or yellow reading only the speed of the cooler?

73 de DO6BJ / Thomas

DO6BJ wrote: Hi Thomas,
You should use the Red and Black wires. Yellow not used(it's speed data from fan to out).
Red should be connected to ExtCTRL power line +12V(SunSDR2 Pro) or +5V(SunSDR2 not PRO) - the same pin 14.
Black wire should be connected to ExtCTRL X7 switch - pin 3.
Schematic diagram is here.

Note: If you uses SunSDR2 Pro with +12V power line on ExtCTRL connector, you can insert serial resistor to reduce fan speed.

Hello Vasily,

Which type of protection diode can I use?

greeting
Thomas (DO6BJ)

hi Thomas,

I use 1N4001 for PA and also one for FAN. It works ok.

GL!

Simon

In the case of a SunSDR2 Pro, where does the +12V come from on pin 14? From within the radio? From an external source?
If from external source, would power be supplied to both pin14 and pin15, the GND?
Not very clear to me as it's not shown on the dia..

What settings have to be made in the control software to have the internal thermostat control operation of the fan? Does column 7 need to be set in any particular way, such as for each band?
Again not very clear to me.

I am trying to use a 24v fan at 12V as it is very quiet at that voltage.
Works great direct from a 12V source direct but I'd like to shut it down when the radio is cool enough.

Thanks
VE3ERQ

The pin 14 has a direct connection to Power supply connector and has the same voltage as an external power supply. Also, pin 14 power line has a 1A fuse and serial diode for protection. The GND 15 pin has a direct connection to common GND of the radio and direct connection to negative pin of the power supply connector.
You should set protection diode in parallel with FAN, cathode to +V, anode to -V. See the following document: eesdr.com/images/Document/SunSDR2_PRO/External%20Devices%20connection%20Diagram_SunSDR2PRO.pdf

You should set "Thermostat" checkbox for normal software control of the fan operation. It doesn't matter what checkboxes were set in the 7-th column before, but it would be better if none, just in case.