Hey, this is my first post on here so go easy on me.
I'm a bit of an electronics amature, but i'm looking to learn.
I've had a go at building a 'Shift Light' circuit for my car using a LM2917 IC (i have attached the circuit diagram to this post), to do this i made an ETCH'ed PCB
Overall the circuit functions as it should, however it seems to be very temperature sensative (the shift setpoint creeps up with ambiant temperature as much as 1500rpm to 5*C)
I've tried replacing the diode that goes to Pin 11 (or the inverting input of the comparitor op-amp) for a zener diode that when fitted in reverse gives a voltage of 0.7v as i assumed that a small signal diode i was using was fluctuating with temperature, however this has made no difference.
Please can someone try and point me in the right direction?
Thanks
Paul
I'm a bit of an electronics amature, but i'm looking to learn.
I've had a go at building a 'Shift Light' circuit for my car using a LM2917 IC (i have attached the circuit diagram to this post), to do this i made an ETCH'ed PCB
Overall the circuit functions as it should, however it seems to be very temperature sensative (the shift setpoint creeps up with ambiant temperature as much as 1500rpm to 5*C)
I've tried replacing the diode that goes to Pin 11 (or the inverting input of the comparitor op-amp) for a zener diode that when fitted in reverse gives a voltage of 0.7v as i assumed that a small signal diode i was using was fluctuating with temperature, however this has made no difference.
Please can someone try and point me in the right direction?
Thanks
Paul
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