Buck supplies

[Steve2381]

Hey all

I bought a hand full of these cheapy buck bang converters off Ebay.... seem pretty good. Are they reliable enough to power an 08m2 off a variable/unstable 24v?
How good are they at actually providing a noise free supply to a Picaxe?

The 24v in question is a battery, but its in a noisy electrical environment.

Just wondered if anyone had used one.

 

[oracacle]

They can be quite noisy. However that doesn't mean it's not ok. It will depend on your circuit weather is good going to be ok or not. If your using ADC then only testing can tell. Make sure you have appropriate decoupling capacitors in place to help things along

 

[inglewoodpete]

I use an LM2575S based buck converter module as a 12v-to-3v battery eliminator for a portable LP gas hot water system. I included an 08M2 to monitor the voltage and do a couple of other tasks. My situation is probably different to yours: the HWS has a gas valve solenoid with an 'operate' winding of just 4 ohms, so I included two series-connected 5 Farad, 2.7v high current capacitors across the 3v supply rail. I had to take extra care with the high-current paths, so that the PIC was not affected by the solenoid's voltage and currents. Not surprisingly, noise from the buck converter was not a problem! (But it did need a pretty big slow-blow fuse to cater for the inrush current when it first charged that 2.5F capacitor.)

 

[geoff07]

I use a Chinese LM2596S-based converter to drive a 40X2, and 08M2, and associated bits at 5v from a 13v supply with no issues. Make sure you use the normal decoupling caps.

 

[The bear]

I also use the Chinese LM2596S-based converters, got six running continuously. OK, no great current demands and input volts around 12 volts.
Very compact and useful.
bear..