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Topic: 24V in but less than 5V out on 2N4401 (Read 930 times) previous topic - next topic

mOskit

I actually did a prototype. It was just about making another 2 sided board which frustrating me a lot when I try to lineup transfer paper. Simply I had 2 pnp proxy switches, and now I have 8, so I trying to interface those 8 into 2 original inputs  on the machinery with individual behaviour.

Grumpy_Mike

Why the obsession with a PCB? Why not make stuff on strip board?

mOskit


justjohn

Why the obsession with a PCB? Why not make stuff on strip board?
Trying to be pro for my bosses :)
A properly made strip board can be even more impressive. :-)
Especially compared to a custom PCB, having had a little surgery to make repairs, and perhaps even with a little bit of smoke arising from various places. :-)

jremington

A PCB that doesn't work properly is, unfortunately, not impressive.

mOskit

Lets ignore the PCB for now.

Is this the right place for the flyback diode (D3, D4)? considering that there is a relay it might be handy to have that.

Grumpy_Mike

#21
Dec 15, 2017, 10:30 am Last Edit: Dec 15, 2017, 10:32 am by Grumpy_Mike
Is all you are switching is a relay coil then why have a top switch in the first place? Just use one transistor as a bottom switch.

As the diodes are not connected they will do no good anyway.

mOskit

#22
Dec 15, 2017, 10:36 am Last Edit: Dec 15, 2017, 10:40 am by mOskit
I have mentioned before Mike, there was 2 pnp sensors, so the machinery receives  24V on signal line, i don`t know what is it switching yet could be 24V relay or something else. i know i`m guessing right now but... in worse case scenario I`m just not going to solder those diodes on board.
Edit.
See attached, this is what i`ve done according to materials i have found online

Grumpy_Mike

#23
Dec 15, 2017, 11:04 am Last Edit: Dec 15, 2017, 11:05 am by Grumpy_Mike
No I wouldn't bother with that, it will only prevent the device from switching off hard and the device could be powered for quite a time after you command it off.

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