gres
Full Member level 4
At https://www.elektroda.pl/rtvforum/topic1475860.html you can find original text, and file to download – diagram for power supply for any number of LED diodes works with 230 VAC. Number of diodes is limited only from top, cause number of diodes in series connection ( exactly sum of voltage dorp in conduct direction should be lower than 320V. Current is DC autonomously of how many diodes we plug and it is 20mA. Device is suitable for each application that need a lot of light, such as aquarium, night lamps etc.
System consist power supply with overload safety system – varistor on input, and current source that force Constance current.
T1 transistor could be any low power npn. T2 could be transistor with emitter voltage 400V and right power because it has to work on radiator. For testing I used very cheap BU208 and BU326. Radiator you have to choose in experimental way because it’s capacity must be set correctly to voltage drop at diodes. As more diodes there is lower power loose at transistor and it might be situation that with right number of diodes radiator won’t be necessary.
While testing I made short circuit, double side aspis radiator, with dimensions – half cigarettes pack was enough. Unfortunately I don’t have board sample.
I wan’t to admire that it’s not economic to use system for 1,5 or 10 diodes. It this case it’s better to make typical power supply with transformer, but in case of use much more this system is perfect.
System consist power supply with overload safety system – varistor on input, and current source that force Constance current.
T1 transistor could be any low power npn. T2 could be transistor with emitter voltage 400V and right power because it has to work on radiator. For testing I used very cheap BU208 and BU326. Radiator you have to choose in experimental way because it’s capacity must be set correctly to voltage drop at diodes. As more diodes there is lower power loose at transistor and it might be situation that with right number of diodes radiator won’t be necessary.
While testing I made short circuit, double side aspis radiator, with dimensions – half cigarettes pack was enough. Unfortunately I don’t have board sample.
I wan’t to admire that it’s not economic to use system for 1,5 or 10 diodes. It this case it’s better to make typical power supply with transformer, but in case of use much more this system is perfect.