Hi,
this is a picture of webasto bbw46 flame sensor circuit. http://img262.imageshack.us/img262/7519/fotod.png
When there is no flame, fotodiode isn't "open", and when there is, steel near fotodiode starts to glow causing the voltage difference around the diode drops to about zero.
My problem is that when weather is cold, it takes too long for steel to get red hot causing that webasto thinks there is some problem with fuel or glow plug etc. Voltage difference only gets to about 8V. So what I need is a small and simple circuit to react this 4v change of the diode. Then it could be used with small relay or mosfet in parallel with original fotodiode. Then it's fooling the control box there is flame by making short circuit in parallel with original fotodiode.
Very annoing problem, what would you say, what's the best way to do this?
Thanks and sorry for my english.
Greetings from icy cold Finland (-22F)
this is a picture of webasto bbw46 flame sensor circuit. http://img262.imageshack.us/img262/7519/fotod.png
When there is no flame, fotodiode isn't "open", and when there is, steel near fotodiode starts to glow causing the voltage difference around the diode drops to about zero.
My problem is that when weather is cold, it takes too long for steel to get red hot causing that webasto thinks there is some problem with fuel or glow plug etc. Voltage difference only gets to about 8V. So what I need is a small and simple circuit to react this 4v change of the diode. Then it could be used with small relay or mosfet in parallel with original fotodiode. Then it's fooling the control box there is flame by making short circuit in parallel with original fotodiode.
Very annoing problem, what would you say, what's the best way to do this?
Thanks and sorry for my english.
Greetings from icy cold Finland (-22F)