Air Breeze 300w 12v wind turbine controller board diode D4

[Johncat44]

Hi there, looking for some info on an Air breeze controller board. I'm looking for the value of the D4 diode as in the attached pics. I actually knocked it off whilst dismantling the board and was lucky to see it as its very small. I did solder it back on but feared I soldered it on wrong way round. I tested the the assembled turbine today as per tests in manual and the diode was smoking and melted. So if anyone has any experience of repairing these boards I'd appreciate some pointers. Thanks

 

[William_H]

From the circuit D4 appears to be a protection diode on the output of the alternator where it feeds the regulator for the control processor. it is connected anode to negative so normally would not conduct. But would conduct if any negative spikes appear on output of alternator rectifier. it may in fact be a zener diode which break down as in conducts when hit with a voltage above it's rated zener voltage in the normally non conducting direction.
So if you fitted the low power diode (zener or not) in the wrong way ie so it conducts with normal positive supply it would smoke itself to death.
I would suggest replace it with a 20volt 300mw zener diode with cathode (band or tail of arrow) to positive line.
However I may have it all wrong as normally using a zener for protection or regulation you have a series resistor in the line to limit zener current and control high voltage.
In fact I think you may find the whole device works Ok without that diode. But it must have been fitted for a reason. ol'will

 

[Johncat44]

Hi there, looking for some info on an Air breeze controller board. I'm looking for the value of the D4 diode as in the attached pics. I actually knocked it off whilst dismantling the board and was lucky to see it as its very small. I did solder it back on but feared I soldered it on wrong way round. I tested the the assembled turbine today as per tests in manual and the diode was smoking and melted. So if anyone has any experience of repairing these boards I'd appreciate some pointers. ThanksView attachment 135504View attachment 135505View attachment 135506View attachment 135507

Hi William, thank you for your help and explanation. I’ve just ordered the diode and I have spoke to a neighbour this morning who has offered to assist in me soldering it the correct way round. I’m confident that the turbine will work again.
many thanks, John

 

[VicS]

From the circuit D4 appears to be a protection diode on the output of the alternator where it feeds the regulator for the control processor. it is connected anode to negative so normally would not conduct. But would conduct if any negative spikes appear on output of alternator rectifier. it may in fact be a zener diode which break down as in conducts when hit with a voltage above it's rated zener voltage in the normally non conducting direction.
So if you fitted the low power diode (zener or not) in the wrong way ie so it conducts with normal positive supply it would smoke itself to death.
I would suggest replace it with a 20volt 300mw zener diode with cathode (band or tail of arrow) to positive line.
However I may have it all wrong as normally using a zener for protection or regulation you have a series resistor in the line to limit zener current and control high voltage.
In fact I think you may find the whole device works Ok without that diode. But it must have been fitted for a reason. ol'will

It is not shown as a Zenner. Elsewhere a diode (D6) is shown as a Zenner.

I'd, therefore, assume it is not a Zenner and replace it with a silicon diode with adequate PIV (50v... ? ) but I have no idea what max I_f to suggest.
.