GaryGavlaar
Free Member
- Feb 13, 2023
- 163
- 54
- Funster No
- 93,987
- MH
- Bessacarr E695
For some completeness to this thread, I eventually found this post on another forum. I'm still yet to receive my new igniter cable to see if I can get this working. However this description of how the single cable igniter works to sense a flame also i thought was decent.....
Firstly the spark generator is actually a reigniter rather than an igniter. This means it constantly checks the flame integrity and restarts the high voltage pulses to create sparks if the flame extinguishes for any reason. So in normal operation, should the flame be blown out it will be automatically be re-lit.
The way it achieves this is by exploiting the fact that the resistance through the ionised gases in a flame is significantly lower than through air. The reigniter unit measures the resistance between the probe tip and the "earth" terminal of the reigniter unit - doing this between the HV pulses.
This in turn means you need to pay attention to the following points to ensure the resistance measuring current path around the circuit is OK
1. Ensure probe tip is touching the outer part of the flame
2 Ensure the connection from the reigniter to the frame ( the chassis or earth connection) is good (not loose or corroded)
Then the low voltage circuit from the reigniter probe, the ionised flame gas, the brass flame tube, the fridge chassis, the reigniter earth connection should be complete and once a flame is lit current should flow and trigger the reigniter to stop HV pulses. Note that only about 5 mA flows in this measuring circuit - so connections have to be good.