Hi there,
Guys Im new here so pwease take it easy on me ^_^ and you could say that Im a total noob.
Anyways Ive got me some TDA2030A chips and I hope to make something out of these chips (as a starter project xD) I have all the schematics and everything except for the schematics and ratings of the power supply so can you pls help me with that by providing me some kind of guide on making the power supply for an amp powered by TDA2030A ive decided to make one with the single power not the split one
Guys Im new here so pwease take it easy on me ^_^ and you could say that Im a total noob.
Anyways Ive got me some TDA2030A chips and I hope to make something out of these chips (as a starter project xD) I have all the schematics and everything except for the schematics and ratings of the power supply so can you pls help me with that by providing me some kind of guide on making the power supply for an amp powered by TDA2030A ive decided to make one with the single power not the split one
I've built a TDA2030A amp, ran it off a regulated split supply. For some undetermined reason it sounded awful at first but then was fine after a few hours running in. Nice little amp.
You could run it off a wall-wart.
Absolute maximum voltage for TDA2030A is 44V, minimum is 12V.
Allowing for mains supply going 10% higher than nominal a 40V adapter would be the maximum. Allowing for 20% low mains, a 15V adapter would be the minimum. Current rating I'd reckon about 1A for a 15V supply, up to 3 amps for a 40 volt. You might get away with less.
Since mains adapters are usually double-insulated and have no earth connection, you would need to run a separate connection from your amp to mains earth for safety.
If you want to build your own PSU, TDA2030A datasheet recommends:
-- 24 Volt transformer (50VA)
-- bridge rectifier
-- 3300uF reservoir capacitor
It's on page 12.
http://www.st.com/stonline/products/literature/ds/1459/tda2030a.pdf
You can google up datasheets for pretty much any component. They are useful.
There should be a fuse before the transformer, about 200mA. Should be slow-blow, to allow for inrush current at switch-on.
Power switch should come after the fuse.
Transformer type could be R-core, UI-core, EI-core, toroidal, or other... Different people have different ideas about which is best, but any mains transformer will work. A transformer with a 24V secondary at the highest (or two 12V secondaries connected in series) should be 50VA. A lower voltage secondary allows to reduce the VA rating proportionately, but don't go lower than 12V.
DC voltage will be roughly 1.4 times the tranny's secondary voltage.
Put a 275V or 250V transient suppressor (e.g.a metal oxide varistor) across the transformer primary to protect it from voltage spikes on the mains. MOVs may burn out eventually. Higher joule ratings are tougher, but physically larger.
You can build the bridge out of four separate rectifier diodes, but for a first build a rectifier block is very convenient. 200V is a sensible margin for safety, higher voltage rating does no harm. Higher current ratings will be more reliable and run cooler -- KBPC2502 would be bulletproof. Bridges with lower current ratings may need heatsinking.
The capacitor will be an aluminium electrolytic. Make sure it has high ripple current rating, and a voltage rating about twice the expected DC voltage (i.e. 63 Volt rating for a 24V transformer) or higher. Also make damn sure you connect the capacitor the right way round, with the negative terminal to ground. Get those three things right or cap will go bang.
Alternative to 3300uF, you could use one 4700uF, or two (or more) 2200uF in parallel, or three (or more) 1000uF in parallel. Several smaller caps in parallel will actually perform better than one large cap. Bigger total capacitance is better, up to a point.
Keep wiring between these components short, and twist the pairs of wires tightly together from the transformer to the bridge, and from the bridge to the capacitor. Use reasonably thick wires. Keep the electrolytic away from stuff which gets hot as electros dry out over time, quicker if heated.
And keep the power supply away from the amplifier circuit, or your amp will pick up hum from the transformer. Putting the transformer at different angle to the circuit can help a bit.
Optional extras include:
You could put a bleeder resistor across the capacitor to let it discharge when switched off. Use a high value to minimise current draw, I'd say 6k8 or greater, 1W or 2W preferred so it doesn't get too hot.
It's a good idea to put a fast-blow fuse rated a bit higher than the maximum expected current draw from the amp in the supply line after the capacitor. The power supply will be more expensive than the amplifier - you don't want a fault in the amp to fry the PSU as well.
If you have a way to measure inductance and capacitance in the transformer or an oscilloscope you might consider an RC snubber across the AC terminals of the bridge, but if you can't make the necessary measurements it's probably better not to use a snubber.
At first power up, highly recommended to use the light bulb protection circuit described here
Remember that the mains is deadly dangerous. Power supply unit must be solidly constructed, not a lash-up! Proper safety-earthing is imperative.
Articles on PSU construction can be found at Decibel Dungeon and Rod Elliott's site, and I'm sure you could google up others.
Don't embark on building your own PSU until you're certain you know what you're doing.
You could run it off a wall-wart.
Absolute maximum voltage for TDA2030A is 44V, minimum is 12V.
Allowing for mains supply going 10% higher than nominal a 40V adapter would be the maximum. Allowing for 20% low mains, a 15V adapter would be the minimum. Current rating I'd reckon about 1A for a 15V supply, up to 3 amps for a 40 volt. You might get away with less.
Since mains adapters are usually double-insulated and have no earth connection, you would need to run a separate connection from your amp to mains earth for safety.
If you want to build your own PSU, TDA2030A datasheet recommends:
-- 24 Volt transformer (50VA)
-- bridge rectifier
-- 3300uF reservoir capacitor
It's on page 12.
http://www.st.com/stonline/products/literature/ds/1459/tda2030a.pdf
You can google up datasheets for pretty much any component. They are useful.
There should be a fuse before the transformer, about 200mA. Should be slow-blow, to allow for inrush current at switch-on.
Power switch should come after the fuse.
Transformer type could be R-core, UI-core, EI-core, toroidal, or other... Different people have different ideas about which is best, but any mains transformer will work. A transformer with a 24V secondary at the highest (or two 12V secondaries connected in series) should be 50VA. A lower voltage secondary allows to reduce the VA rating proportionately, but don't go lower than 12V.
DC voltage will be roughly 1.4 times the tranny's secondary voltage.
Put a 275V or 250V transient suppressor (e.g.a metal oxide varistor) across the transformer primary to protect it from voltage spikes on the mains. MOVs may burn out eventually. Higher joule ratings are tougher, but physically larger.
You can build the bridge out of four separate rectifier diodes, but for a first build a rectifier block is very convenient. 200V is a sensible margin for safety, higher voltage rating does no harm. Higher current ratings will be more reliable and run cooler -- KBPC2502 would be bulletproof. Bridges with lower current ratings may need heatsinking.
The capacitor will be an aluminium electrolytic. Make sure it has high ripple current rating, and a voltage rating about twice the expected DC voltage (i.e. 63 Volt rating for a 24V transformer) or higher. Also make damn sure you connect the capacitor the right way round, with the negative terminal to ground. Get those three things right or cap will go bang.
Alternative to 3300uF, you could use one 4700uF, or two (or more) 2200uF in parallel, or three (or more) 1000uF in parallel. Several smaller caps in parallel will actually perform better than one large cap. Bigger total capacitance is better, up to a point.
Keep wiring between these components short, and twist the pairs of wires tightly together from the transformer to the bridge, and from the bridge to the capacitor. Use reasonably thick wires. Keep the electrolytic away from stuff which gets hot as electros dry out over time, quicker if heated.
And keep the power supply away from the amplifier circuit, or your amp will pick up hum from the transformer. Putting the transformer at different angle to the circuit can help a bit.
Optional extras include:
You could put a bleeder resistor across the capacitor to let it discharge when switched off. Use a high value to minimise current draw, I'd say 6k8 or greater, 1W or 2W preferred so it doesn't get too hot.
It's a good idea to put a fast-blow fuse rated a bit higher than the maximum expected current draw from the amp in the supply line after the capacitor. The power supply will be more expensive than the amplifier - you don't want a fault in the amp to fry the PSU as well.
If you have a way to measure inductance and capacitance in the transformer or an oscilloscope you might consider an RC snubber across the AC terminals of the bridge, but if you can't make the necessary measurements it's probably better not to use a snubber.
At first power up, highly recommended to use the light bulb protection circuit described here
Remember that the mains is deadly dangerous. Power supply unit must be solidly constructed, not a lash-up! Proper safety-earthing is imperative.
Articles on PSU construction can be found at Decibel Dungeon and Rod Elliott's site, and I'm sure you could google up others.
Don't embark on building your own PSU until you're certain you know what you're doing.
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