I have designed the attached baterry indicator circuit for a 12 volt battry but for some reason in multisim it just won't work, was working before I put in the 100 and 200 R resistors in series and was just using a pot in their place.
The idea is that this will be used with a tri-colour led, so read is to come on under 12.5 volts and green is to come on over 11.5. so with a tricolour led between 11.5 and 12.5 both lights are on and it goes yellow/orange.
Any suggestions of what I'm missing ?
does anyone know of some good resources for design using comparators ? I can remember what the configurations can do but now how they are wired up.
A very simple battery monitor can be made with a dual-color LED and a few surrounding components. The LED produces orange when the red and green LEDs are illuminated.
The following circuit turns on the red LED below 10.5v
The orange LED illuminates between 10.5v and 11.6v.
The green LED illuminates above 11.6v
I think you could simplify your circuit if you use the same voltage source to both vin pins on the comparators, then use seperate vrefs, and invert the logic on the vlow side.
I bet I did not make sense. I am not very articulate at times
yes the zener is to create a voltage reference at 5 volts approx 1/3 the cicuits max and 1/2 the min, the 100 and 200 ohm voltage devider drops the battery voltage to 1/3 so that the 15 volt scale is adapted to the circuits 5 volt scale
Okay, I think I got it now, your 100 ohm is on the hairy edge of the threshold. You need a pot for the 100 ohm. With your circuit as drawn, I computed 3.666v and threshold needs 3.667v. More of a sim thing, I think you need a pot for the 100 ohm.
Okay, I think I got it now, your 100 ohm is on the hairy edge of the threshold. You need a pot for the 100 ohm. With your circuit as drawn, I computed 3.666v and threshold needs 3.667v. More of a sim thing, I think you need a pot for the 100 ohm.
you need to bear in mind that the power supply will vary from 10-15.5 volts, I've tried a range of voltages and its just dead but I can't figure were I went wrong. I did have a pot for the 100 ohm one before but then got the circuit worked out to the correct voltage levels as before it worked when on low voltages like 2.5
the low come on at 12.5 V but the high at above 11.5 so they are both on between 11.5 and 12.5 making it orange. Its a starngle logic I know but the most component efficient i could think of and quite accurate, but at present acording to multisim its stone dead
the low come on at 12.5 V but the high at above 11.5 so they are both on between 11.5 and 12.5 making it orange. Its a starngle logic I know but the most component efficient i could think of and quite accurate, but at present acording to multisim its stone dead
yes I'm refering to my circuit. I don't think multisim wants all power terminals connected as I can't connect to the blank ones if I wanted to, as soon as I conected one VCC the red "X" appeared on the other and it would not connect to. like wise on GND. perhaps I'll try and make it in the flesh on a breadboard as i just have the components (well will have to dig out the leds from wherre ever I lost them)