ESP8266 Community Forum

- Fri Jan 13, 2017 9:02 am #60951

The diode is placed across the coil to give the inductor current a path when the transistor is OFF (open).

I found the datasheet here: http://rabbitmax.com/files/SONGLE-SRD-05VDC-SL-C.pdf

Yes, I understand now. PNP are from - to +. so the Transistor side of the coil is the last place you could discharge, it now makes sense (I think). if I used a NPN then would you still need the diode?

- Fri Jan 13, 2017 2:40 pm #60969 The example circuit that I provided used a NPN transistor.
A flyback diode is recommended for a PNP relay driver too.

- Wed Sep 26, 2018 11:27 pm #78409

I had a similar problem a while back, weak signal from the output pin had to be boosted (it was an analog signal too, iirc, from a DAC). Someone recommended I use an op-amp setup to boost the signal, and it worked a treat!

I still have the unit, built it easily with just one chip, a 4-op amp LM324 jobbie.

By the way, like yourself, I am more of a programmer, and know very little about electronics. So if I could do it, you probably could, too. The design is something like this: http://www.eleccircuit.com/increase-out ... 85ma-size/

Only thing I'm not sure is if the 85mA output is enough for you.

Hi,

If you are working on LM324 then you should first download this Proteus Simulation of LM324. I think that will help you in understanding this audio amplifier.

Thanks.

- Thu Sep 27, 2018 3:22 am #78410

If you are working on LM324 then you should

How does that relate to this topic?

Stop promoting your own website, all you ever contributed up to now always included some link to your site, which is considered as spamming.
If you're not happy with the number of visits you're getting, please consider improving your website instead.

Assumption is the mother of all f*ckups. At least: that's what I'm assuming.