gres
Full Member level 4
When I was cleaning my old stuff I decided to modify old laboratory feeder. I exchanged transformer to bigger one cause I need 2 A ( nothing amazing, but before 1A was strong limit for me). I rebuilt casing as old one couldn’t hold new/old staff ( transformer has many years and makes some buzzing noise, but not much) Casing that I used is toll and I realized that something is missing there. So I designed simple Voltmeter at 2xLM3914 that control simple diode rubber. I used two colors to makes it nicer. Device should flash 10 green diodes until 15V and then from the beginning but with red color.
0..15V => [Z][Z][Z][Z][Z][ ][ ][ ][ ][ ] [z] =[g] green
15..30V => [C][C][C][C][ ][ ][ ][ ][ ][ ] [c]=[r] red
diagram
So far i tested device at symulator.
How it works?
In to input (leg 5) comes 0..2,7V (after had past thought divider). Rest part of system is classic application LM3914 except R3 resistor. Diodes flash with 1,5V step. Resistor R3 is for voltages lower then 15V and it gives additional voltage to leg 9 LM3914 (mode ->+power= diode rubber; mass or not connected= single diodes). At moment passes through 15V at leg LM3914 (U2) appear mass potential that cause all green diodes turning off. Now red diodes starts to flash with 1,5V step until reached 30V.
R1 and R2 elements should have the same values as I been told, otherwise might be necessary to split divider. R3 could has resistance between 10…20k ohm about <5.8 k green diodes wan’t goes down, >20k will start flash in one after one mode ( green cause red will no change)
I hope I would get square diodes to get better effect.
0..15V => [Z][Z][Z][Z][Z][ ][ ][ ][ ][ ] [z] =[g] green
15..30V => [C][C][C][C][ ][ ][ ][ ][ ][ ] [c]=[r] red
diagram
So far i tested device at symulator.
How it works?
In to input (leg 5) comes 0..2,7V (after had past thought divider). Rest part of system is classic application LM3914 except R3 resistor. Diodes flash with 1,5V step. Resistor R3 is for voltages lower then 15V and it gives additional voltage to leg 9 LM3914 (mode ->+power= diode rubber; mass or not connected= single diodes). At moment passes through 15V at leg LM3914 (U2) appear mass potential that cause all green diodes turning off. Now red diodes starts to flash with 1,5V step until reached 30V.
R1 and R2 elements should have the same values as I been told, otherwise might be necessary to split divider. R3 could has resistance between 10…20k ohm about <5.8 k green diodes wan’t goes down, >20k will start flash in one after one mode ( green cause red will no change)
I hope I would get square diodes to get better effect.