A little help with gauge reversal circuit please.
Hi folks. Hope you can help.
I have an antique 1968 gauge and have replaced the level sender with new which of course is incompatible as the originals are no longer made.
I know this has been discussed before - http://forum.allaboutcircuits.com/showthread.php?t=29644 (many thanks to Jack-K & SgtWookie)
All was going well using an LM2904 but as I needed more current (about 100mA) I added an output PNP, but this has led to an unwanted offset of 0.8V which means I cannot get close to zero. I need to get to 0.5v and am at present on about 1.3V minimum.
Is there a way to increase current handling from the LM2904 without adding an offset or do I need another op amp?
I'm fairly new to this level of electronics and am self taught but enjoying it, so any help would be appreciated.
Many thanks.
Hi folks. Hope you can help.
I have an antique 1968 gauge and have replaced the level sender with new which of course is incompatible as the originals are no longer made.
I know this has been discussed before - http://forum.allaboutcircuits.com/showthread.php?t=29644 (many thanks to Jack-K & SgtWookie)
All was going well using an LM2904 but as I needed more current (about 100mA) I added an output PNP, but this has led to an unwanted offset of 0.8V which means I cannot get close to zero. I need to get to 0.5v and am at present on about 1.3V minimum.
Is there a way to increase current handling from the LM2904 without adding an offset or do I need another op amp?
I'm fairly new to this level of electronics and am self taught but enjoying it, so any help would be appreciated.
Many thanks.