Hello, I have decided to embark on an electronics project for my own enjoyment and gain of understanding of electronics. I'd like to have 3 x LM3914 dot/bar graph chips together to show the position of Clutch, Brake & Accelerator pedals in a car using Yellow, Red & Green LEDs respectively linked to slide pots attatched to the pedals.
I think I have got the basic circuit figured out but there are a few things I am unsure of, so I have joined this forum to hopefully get some help
I'd like to be able to switch all 3 between dot/bar using 1 switch and have the ability to dim all 3 using a pot. I am not sure the way I have it hooked up is correct. The switch is easy, but I am not sure how to select values for a pot (slide or rotary). Aside from the resistors on the LEDs, which I've got as 500 Ohm 0.5W (based on an online resistor calculator). In reality I'd use two 1000 Ohm 0.25W in parallel, as I have loads of them to hand. I am not sure of the other resistor values I'd need. I can find quite a lot of info on here and elsewhere for the LM3914 but not a vast amount about running it at 12V.
I have downloaded LTSpice and built up the circuit to where I think it should be. Most of the components have been left 'as is' apart from the LED resistors. I can make the circuit 'run' but as for how to interpret the results I've hit a dead end.
I'd be happy to give it a go and actually build up the circuit on a board but I kinda want to limit the number of things I blow up!
Thanks in advance (and go easy on me, it's my first day!)
I think I have got the basic circuit figured out but there are a few things I am unsure of, so I have joined this forum to hopefully get some help
I'd like to be able to switch all 3 between dot/bar using 1 switch and have the ability to dim all 3 using a pot. I am not sure the way I have it hooked up is correct. The switch is easy, but I am not sure how to select values for a pot (slide or rotary). Aside from the resistors on the LEDs, which I've got as 500 Ohm 0.5W (based on an online resistor calculator). In reality I'd use two 1000 Ohm 0.25W in parallel, as I have loads of them to hand. I am not sure of the other resistor values I'd need. I can find quite a lot of info on here and elsewhere for the LM3914 but not a vast amount about running it at 12V.
I have downloaded LTSpice and built up the circuit to where I think it should be. Most of the components have been left 'as is' apart from the LED resistors. I can make the circuit 'run' but as for how to interpret the results I've hit a dead end.
I'd be happy to give it a go and actually build up the circuit on a board but I kinda want to limit the number of things I blow up!
Thanks in advance (and go easy on me, it's my first day!)
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