Electronics > Beginners

555 timer pwm dimmer for higher voltage

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Martichoke:
Hi all,
My plan is to add some dimming to my 2835 led strip.
The strip is powered from 240v(ish)ac into GBU810, off memory putting out 220v(ish)dc.

I really like the idea of making my own dimmer and would like to know if its okay to use a 555 timer pwm as a base schenatic and simply change the components for higher rated equivalents.
1. Is this even possible/ the safest and most practical path?
If yes,
How/where can i easily find a higher rated benchmark equivalent? (a 555 timer that is higher rated than 15v, etc
If no,
Can you please point me in a good direction  ;D

On a side note, I'm an electrician and can safely practice with higher current.

Thanks,
Choke

Zero999:
It's a bridge rectifier, so you really have nearly 240√2 = 340V peak, unfiltered DC, not 220VDC.
https://www.diodes.com/assets/Datasheets/ds21227.pdf

The 555 timer circuit could theoretically be run off a 12V power supply and drive a transistor rated to >400V to PWM the LED strip, but it's not a beginner project. The whole 555 circuit would float at the mains voltage, thus would need to be treated with the same precautions as the mains.

Martichoke:
Ah thanks for the correction, i was to lazy to bring up the datasheet and i installed it months ago so couldnt quite remember

Thanks for the transistor idea, ill try that.

Zero999:

--- Quote from: Martichoke on March 18, 2019, 08:03:47 pm ---Ah thanks for the correction, i was to lazy to bring up the datasheet and i installed it months ago so couldnt quite remember

Thanks for the transistor idea, ill try that.

--- End quote ---
I don't think I made myself clear, regarding the danger. The whole 555 timer circuit, including anything connected to it: the 12V power supply, potentiometer which must be plastic, by the way, etc. will all be live at mains voltage. Observe all of the usual precautions when working with mains voltages.

Why not simply dump 240V LED strip and replace it with 12V LED strip? The 555 timer circuit will safely work off 12V, with no problems and there's no need to worry about getting a shock off it.

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