G'day all. I have a diesel heater installed in our van. It is connected direct to the batteries as per makers instructions. Works very well. When the heater is switched on and until it is switched off, it causes the am radio is be unusable. There is a heap of static on the radio. When the heater is switched on, the radio works quite well.
Any suggestions please?
Thank you.
Robert
Tony Bev said
08:48 PM Aug 14, 2018
I have successfully used FERRITE VOLTAGE SPIKE on the positive and negative wires of the radio, to stop interference
But ...
I had no idea where the interference was coming from, and do not have a Diesel Heater
They come in different sizes, and just clip around the wires
Below is a link to some at JayCar, which seems to be a national company
I understand these heaters use a solenoid type pump to force the diesel into the combustion chamber and it is most likely poor design of the drive electronics for this pump which is causing the problem.
First: check all wiring and ground connections.
Next: identify the supply wires for the pump and wrap as many turn as possible around the split ferrites mentioned by Tony - this should be done as close to the drive electronics as possible. Also try multiple ferrites in series.
If the above does not fix the problem then a more complex filter with inductance and capacitance will be required.
Also try a power diode (5A or so) in *reverse* bias mode across the pump and as close to it as possible - ie. anode to pump negative, cathode to pump positive.
Unfortunately few designers of electronics give a toss about spurious RF emissions especially in the MF and HF bands unless they are forced to by law and even then many ignore it.
Please keep us informed of your progress, or lack thereof, this is a subject dear to my heart.
Robreen said
05:26 PM Aug 15, 2018
G'day all. Thank you for your replies. I will check all connections and joints for the heater and get some of those ferries from jaycar and attach a couple near the pump and radio. We will see. Let the forum know.
Regards Robert
Robreen said
12:25 PM Aug 16, 2018
G'day all again. More about my problem. The interference only occurs when the fan for the heater is on without the heater being on. A portable radio is also affected when the fan is on.
I have cleaned all the battery connections. They are nice and shiny. The problem is still occurring. The heater is of Chinese make.
Regards Robert
Mike Harding said
04:47 PM Aug 16, 2018
Robreen wrote:
G'day all again. More about my problem. The interference only occurs when the fan for the heater is on without the heater being on. A portable radio is also affected when the fan is on. I have cleaned all the battery connections. They are nice and shiny. The problem is still occurring. The heater is of Chinese make. Regards Robert
My comments still apply. Replace "pump" with "fan".
Bush walker said
07:06 PM Aug 27, 2018
I think tat you will find that the static is caused by the fan motor If you try fitting a capacitor noise suppressor like the ones used on cars for the alternator and coil it may help solve your problem
I have successfully used FERRITE VOLTAGE SPIKE on the positive and negative wires of the radio, to stop interference
But ...
I had no idea where the interference was coming from, and do not have a Diesel Heater
They come in different sizes, and just clip around the wires
Below is a link to some at JayCar, which seems to be a national company
https://www.jaycar.com.au/u25-ferrite-voltage-spike-protectors-noise-suppressors-each/p/LF1290
I understand these heaters use a solenoid type pump to force the diesel into the combustion chamber and it is most likely poor design of the drive electronics for this pump which is causing the problem.
First: check all wiring and ground connections.
Next: identify the supply wires for the pump and wrap as many turn as possible around the split ferrites mentioned by Tony - this should be done as close to the drive electronics as possible. Also try multiple ferrites in series.
If the above does not fix the problem then a more complex filter with inductance and capacitance will be required.
Also try a power diode (5A or so) in *reverse* bias mode across the pump and as close to it as possible - ie. anode to pump negative, cathode to pump positive.
Unfortunately few designers of electronics give a toss about spurious RF emissions especially in the MF and HF bands unless they are forced to by law and even then many ignore it.
Please keep us informed of your progress, or lack thereof, this is a subject dear to my heart.
My comments still apply. Replace "pump" with "fan".
I think tat you will find that the static is caused by the fan motor If you try fitting a capacitor noise suppressor like the ones used on cars for the alternator and coil it may help solve your problem