A nice simple circuit for a change
Added 2021-03-30 23:23:07 +0000 UTCInside a dimmable Poundland light.
It does actually have circuitry besides the potentiometer.
Comments
There are schematics for 555's as simple PWM controllers, but with limited range. You get low gate voltage MOSFETs like the A2SHB. I think I've got a Chinese PWM controller here with a 555 creating a sawtooth and a comparator comparing it to a pot.
Big Clive
2021-04-07 03:52:45 +0000 UTCEver since my very first £6 Woolworths headphones with inline volume control I've harboured an antipathy to pots used at low impedance. But it's a very neat, simple solution and you can't really expect more for £1. Following a previous post, I was wondering how easy a 12Vdc 30W PWM switcher would be with a pot and 555. I don't know if there are 555s that run at 12V, but perhaps something from 4000 series like 4538. And can it be made 2 terminal - just a simple inline control? My biggest concern is driving the FET (if a FET is used) hard enough to avoid linear region dissipation.
Mike Page
2021-04-04 16:33:37 +0000 UTCThe Teleshag supercomputer is based on the real-fake horoscope computer the Televac 86000.
Big Clive
2021-04-03 06:12:57 +0000 UTCThat does look like a good reference circuit. I have a couple dimmers I’ve used on 12 volt automotive cobs but never achieved a good linear progression of brightness with the designs I’ve used. That’s so simple, I think I’ll try to put one together next Saturday during the stream. Btw, I never knew the real name, “Teleshag 62,0000 super computer” ?
Jim
2021-03-31 19:11:12 +0000 UTCIt really has a pot?! I thought it just slid a plastic screen over the window!
Ymir the Frost Giant
2021-03-31 12:51:59 +0000 UTCGreat little device, the phrase "fully rechargeable" always anuses me, what is a partially rechargeable device like?
Dr Andy Hill
2021-03-31 07:00:44 +0000 UTCShort and sweet. Nice wee thing as usual from Dealz.
John Carr
2021-03-31 03:21:53 +0000 UTCThat potentiometer and switch would work perfect for a tig thumb controller, just put 100pfF 100v decoupling film caps in and that is basically what is in my $200 thumb controller
Coil B
2021-03-31 02:03:13 +0000 UTCWhy not put a resistor in series between the transistor and the COB? That sounds like something you'd do for the edification of your fans. :-)
Mike Bird
2021-03-30 23:37:20 +0000 UTCneat little thing!
GL_1_Code1_1A
2021-03-30 23:36:54 +0000 UTC
