Notifications
Clear all
Power Supply & Batteries
5
Posts
4
Users
2
Likes
1,385
Views
Topic starter
2022-01-07 3:14 pm
I'm contemplating building a simple night light circuit to power an LED, so it'll need either 3.3V or 5V DC. I want to plug it into the wall, like all the other night lights out there, but I'm not comfortable working with mains voltages.
I know there are plenty of AC-DC converters, like these:
https://universal-solder.ca/product/ac-dc-voltage-converter-85-265vac-to-12v-400ma-dc/
Are these the best options for me? I've not soldered any wires to handle mains voltages, so I would need different solder and thicker wires.
Another option would be to use a USB phone charger in the wall, and then use it to power the circuit via USB. A bit long winded, but most likely much safer?
Thanks
2022-01-07 4:59 pm
How about just a trip to the $$ store ?
Anything seems possible when you don't know what you're talking about.
Inst-Tech reacted
2022-01-07 5:05 pm
Hi @yurkshirelad,
You need to specify the LED power consumption, allowing for losses in any controller or other circuitry. In practice, this means voltage and current demand.
And if you are not familiar with handling mains voltage connections, I would recommend avoiding them. I would hate for anyone to be hurt.
Maybe look to a local DIY store for power supply for lighting cabinets, etc. with matching LED units?
Take care my friend, Dave
Inst-Tech reacted
2022-01-08 2:06 pm
@yurkshirelad, Came late to the party, but I have to agree with @DaveE on this one..AC power is very dangerous, especially if your not experienced working with it..(only takes 9 mA to stop your heart)..so safety is the name of the game when working with even relatively low voltages down to 50 VAC..
The idea of using a USB power would be great, as they can be anywhere between 800 mA and 2A.
All that would be needed in that case is to decide how many Leds you need to provide the lumens (brightness) and then see the specifications of the Leds for forward voltage, and max current of each Led.
Since the USB power is 5 Vdc, (5v - Led forward voltage)/ led max current = resistor needed. Then voltage across resistor ( 5v - Vdc) =ER1, Max current = Imax , Power (watts = ER1* Imax) for each resistor per led.. Add all the currents up to make sure you are not exceeding the power supply ratings.. best to be safe at no more than 80% of max current of the power supply.
Hope this helps somewhat..good luck, have fun, and be safe!
regards,
LouisR
LouisR
Topic starter
2022-01-08 8:09 pm
Thanks all. I'd rather not mess with mains, though I have done a few times in the past, with varying, tongue tingling results!