Hi! This is my 2nd time posting here, I got help on my first try and hopefully in this one too, thanks in advance!
I am a complete noob in regards with electrical and electronics but I am currently trying right now to build a little amplifier so I need your help.
I already look up on this topic on the internet but unfortunately the diagram I have found was low amperage that would not be feasible for my project...
My amplifier board is TPA3116D2 2x50w+100w, I already tried powering it with 24vdc using bus battery and I was satisfied with the sound it produce, but after I got home I only have 12v "25a" LED PSU, it cannot power my speaker like it used to when I did try it on the 24v Battery...
Now I have here is 12-0-12vac 12a transformer, what I wanted to know is how to convert it to DC without losing much of it's ampere? The TPA3116D2 can handle up to 26vdc 8a if I'm not mistaken so the 12-0-12vac into VDC has no problem, just the ampere part is my concern here...
I would like to ask some diagram and parts need for me to be able to convert AC to DC that will comply with my requirements
one more thing, can I use 18-0-18vac 6amp for the same purpose? if so, what parts needed and diagram also. By paralleling the 18v, does it double the ampere? then converting it to DC will it turn to 24-26vdc 12a?
Do I need rectifier board with capacitors after the conversion? sorry for my ignorance...
Thank you very much and more power to the diyaudio forum...
I am a complete noob in regards with electrical and electronics but I am currently trying right now to build a little amplifier so I need your help.
I already look up on this topic on the internet but unfortunately the diagram I have found was low amperage that would not be feasible for my project...
My amplifier board is TPA3116D2 2x50w+100w, I already tried powering it with 24vdc using bus battery and I was satisfied with the sound it produce, but after I got home I only have 12v "25a" LED PSU, it cannot power my speaker like it used to when I did try it on the 24v Battery...
Now I have here is 12-0-12vac 12a transformer, what I wanted to know is how to convert it to DC without losing much of it's ampere? The TPA3116D2 can handle up to 26vdc 8a if I'm not mistaken so the 12-0-12vac into VDC has no problem, just the ampere part is my concern here...
I would like to ask some diagram and parts need for me to be able to convert AC to DC that will comply with my requirements
one more thing, can I use 18-0-18vac 6amp for the same purpose? if so, what parts needed and diagram also. By paralleling the 18v, does it double the ampere? then converting it to DC will it turn to 24-26vdc 12a?
Do I need rectifier board with capacitors after the conversion? sorry for my ignorance...
Thank you very much and more power to the diyaudio forum...
An externally hosted image should be here but it was not working when we last tested it.
> can I use 18-0-18vac 6amp
Yes.
18VAC will rectify-up to 25V of DC minus diode losses, so 21V-24V.
When run AT full 6 Amps DC the transformer works at 8.4 Amps. So it won't run full power continuously without smoke. However if this is for speech/music reproduction your full-power peaks are far too brief to burn a winding, and your long-term power is about 1/10th of full power. So the transformer load is quite safe.
The two rectifiers must be rated far in excess of 8.4 Amps, 100V. They will get HOT, they need to be on a large heatsink. You want a bolt-on package. For safety and convenience you want a fully-insulated package. Like this: MBRF40250TG.
This low-low impedance you want a BIG capacitor. Over 20,000uFd (20mFd) at over 35V. It may be easier to package as four >5,000uFd caps in parallel.
Yes.
18VAC will rectify-up to 25V of DC minus diode losses, so 21V-24V.
When run AT full 6 Amps DC the transformer works at 8.4 Amps. So it won't run full power continuously without smoke. However if this is for speech/music reproduction your full-power peaks are far too brief to burn a winding, and your long-term power is about 1/10th of full power. So the transformer load is quite safe.
The two rectifiers must be rated far in excess of 8.4 Amps, 100V. They will get HOT, they need to be on a large heatsink. You want a bolt-on package. For safety and convenience you want a fully-insulated package. Like this: MBRF40250TG.
This low-low impedance you want a BIG capacitor. Over 20,000uFd (20mFd) at over 35V. It may be easier to package as four >5,000uFd caps in parallel.
Attachments
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rectifier bridge | eBay
You want this type, cheap, sturdy
1PCS Bridge Rectifier KBPC3510 KBPC-3510 35A 1000V NEW | eBay
https://www.electronics-tutorials.ws/diode/diode_6.html
You want this type, cheap, sturdy
1PCS Bridge Rectifier KBPC3510 KBPC-3510 35A 1000V NEW | eBay
https://www.electronics-tutorials.ws/diode/diode_6.html
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Thanks!
Like what coolnose suggested?
thanks for the reply, I will try to look for that maybe tomorrow, hopefully I could find some of those diodes
Though I'm hesitant about the part being cheap, will that mean it would not for long term use?
The link you give me refreshed me with the rectifier diagram same with the motorcycle too, I would just ask the shops if they sell diode that will be sufficient with what I need...
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Auto rectifiers are not what regulates the voltage. The Voltage is controlled by varying the field winding current input to the alternator.
12VAC windings are going to give you 16 or 32 VDC, ie no good way to get 24VDC. An expensive and complicated option is to use a regulator from 32 down to 24, see amazon.
Actually a "choke input" rectifier would give you about 24VDC from 24VAC, but that means a choke similar in size to the transformer.
25A bridge rectifiers are very common and cheap. I don't think they are made with less than 50V rating. Diodes are tough, and will survive transients of hundreds of amperes. For audio use the average current will only a an amp or two. Your speakers will burn up before you kill a rectifier.
12VAC windings are going to give you 16 or 32 VDC, ie no good way to get 24VDC. An expensive and complicated option is to use a regulator from 32 down to 24, see amazon.
Actually a "choke input" rectifier would give you about 24VDC from 24VAC, but that means a choke similar in size to the transformer.
25A bridge rectifiers are very common and cheap. I don't think they are made with less than 50V rating. Diodes are tough, and will survive transients of hundreds of amperes. For audio use the average current will only a an amp or two. Your speakers will burn up before you kill a rectifier.
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