I am trying to find information if I need flyback diods in paralell with relay when driving them from ULN2003. I am planing to use this relay: [image] Köp Relä SRD 5V 1-pol 10A - 240VAC/28VDC NO/NC till rätt pris @ electrokit Köp Relä SRD 5V 1-pol 10A - 240VAC/28VDC NO/NC Songle - SRD-…

[image] 6v6gt: Are you building a control panel of a fight simulator or similar? I knew there were some smart people here. You are absolutely right. What gave it away? [image] 6v6gt: What microcontroller are you using? The plan is Pokeys57E primarily as an input device with the option…

[image] LarryD: However, when pin 9 is tied to ground for the so called lamp test (relay test) function, you then need to add external kick back diodes across the relay coils as in the right schematic. No you don't! Did you not read my explanation in #8? The switch connects pin 9 to ground.…

And you don't like shift registers? :astonished: I do, but not all software developers have implemented it. I want my hardware to be compatible with ProSim, PMDG (Mobiflight) and ZIBOMOD. If I had been able to make the software I wanted, I would not have wanted this solution at all. Then I want…

Any thoughts about the dil-socket?

[image] sudden81: I already have a Boeing 737 cockpit that I have largely interfaced. I thought there must have been some background to some of the less conventional design decisions in your set up but it looks like you have to maintain compatibility with existing systems. With that Boeing 7…

[image] Paul_B: No you don't! Did you not read my explanation in #8? And we come back to where the diodes should be placed. :nerd_face: Place them at the relay coil, we’ve gone trough this many many times before, from years of field experience, they should be at the coil. :older_man: Pop…

[image] LarryD: [image] Paul_B: No you don't! Did you not read my explanation in #8? And we come back to where the diodes should be placed. :nerd_face: Place them at the relay coil, we’ve gone trough this many many times before, from years of field experience, they should be at the co…

[image] sudden81: Why do almost all drawings online show that you should have plus voltage on pin 9? Because by doing so you are connecting the built in flyback diodes to the positive supply and thus the 'top' of the relays, completing the circuit for them to operate to suppress the voltage s…

ULN2003 + Relay + FlyBack Diod?

Other Hardware General Electronics

PerryBebbington April 19, 2022, 3:45pm 20

@sudden81
Maybe this will help Flyback diodes and why you need them

If you still don't understand then please ask a new question.

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ULN2003 + Relay + FlyBack Diod?

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