I want to use a cheap 5.1 speaker 110 volt amp by disconnecting the transformer's 3 blue leads (10.5 volt x2) to the amp's PC board and replacing it with an inverter that will use a battery source. I do not know very much about electronic circuits so a schematic will not help. I'm looking for an assembled board off of Ebay or ??.
Does something like this exist and if it does, will it work for what I want to do?
thanks
Does something like this exist and if it does, will it work for what I want to do?
thanks
You can use 12 DC inputs instead of AC, without modifying the pcb. The rectifier diodes and
filter capacitors will not be a problem, and will reduce noise. The rectifiers will just conduct
continuously, instead of switching on and off. Do use fuses on the inputs from the batteries,
for safety.
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Thanks Rayma for responding - let me summarize - On the board there is a 3 wire connector (blue black Blue) coming from a transformer that has on the label " 10.5VAC x2 2.2A. Questions to convert to directly to a battery with a fuse.
1. I assume I would need two batteries with the battery ground joined
2. The 2.2A on the label means that I should have a battery pack about that size or larger.
3. I assume that there is some leeway in the voltage since the home line AC voltage can vary from 110 or so to 125 , let's say 10% - Does that mean that I could have an input voltage from around 9.5 volts to maybe 12 volts?
4. Anything else you think I should be aware of to convert this small 110 v amp to DC?
Thanks
1.
1. I assume I would need two batteries with the battery ground joined
2. The 2.2A on the label means that I should have a battery pack about that size or larger.
3. I assume that there is some leeway in the voltage since the home line AC voltage can vary from 110 or so to 125 , let's say 10% - Does that mean that I could have an input voltage from around 9.5 volts to maybe 12 volts?
4. Anything else you think I should be aware of to convert this small 110 v amp to DC?
Thanks
1.
1.
The two batteries will have one positive joined to one negative. Only.
your creating, 12v positive, 0v center, 12v negative.
2.
If the unit really draws 2.2amp.
Then a 2.2amp battery will last maybe half an hour before their dead.
3.
Yup.
4.
If it must run on 12vdc, Why not just use a car amplifier ?
If you must use this amp;
Why not use a normal 12v (car/motorbike) battery to run a 12vdc to 110vac invertor ?
Or.
If you already have the 12vdc supply (like in a car or whatever), Why not just install the above mentioned invertor ?
The two batteries will have one positive joined to one negative. Only.
your creating, 12v positive, 0v center, 12v negative.
2.
If the unit really draws 2.2amp.
Then a 2.2amp battery will last maybe half an hour before their dead.
3.
Yup.
4.
If it must run on 12vdc, Why not just use a car amplifier ?
If you must use this amp;
Why not use a normal 12v (car/motorbike) battery to run a 12vdc to 110vac invertor ?
Or.
If you already have the 12vdc supply (like in a car or whatever), Why not just install the above mentioned invertor ?
1. Right, the + and - are connected together for common, and to the ground input terminal.
2. Depends on the operation time. At least two 12V, 5 A-H batteries are likely to be needed.
3. Probably each battery voltage may vary from 13V down to 10V.
4. Fuse BOTH battery input leads at around twice rated pcb current. Be careful of polarities during hookup.
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Those suggestions about a normal car inverter or a car amplifier are good ones. I already have several of each but this build is for a portable type 5.1 system using components that I have collected over the years. I salvaged a cheap 5.1 amp with remote so I wanted to see if I could use it instead of several of the TDa/TPA low cost amps in my drawer.
1. I'm still not sure what you mean about 0V center as that is outside of my league. I assume I need two battery packs or will one series/parallel do it? If one, then I have will combine the one positive lead into two to go to each of the outside connector prongs (blue from the disconnected transformer)? Then the negative goes to the center (black wire now which I assume is the ground.)
2. If I need two battery packs - I assume the positive lead from each, will go to the outside (blue) prongs and combine the negatives from the two battery packs and place it on the center prong (black)? Is that correct.
3. If either one works above, which do you think is better?
thanks
2.
1. I'm still not sure what you mean about 0V center as that is outside of my league. I assume I need two battery packs or will one series/parallel do it? If one, then I have will combine the one positive lead into two to go to each of the outside connector prongs (blue from the disconnected transformer)? Then the negative goes to the center (black wire now which I assume is the ground.)
2. If I need two battery packs - I assume the positive lead from each, will go to the outside (blue) prongs and combine the negatives from the two battery packs and place it on the center prong (black)? Is that correct.
3. If either one works above, which do you think is better?
thanks
2.
Thanks to both of you: I thought I had responded to Old N Cranky but I don't see it so here it is again:
Good Suggestions about the inverter and car amp - I already have several of each but this build is for a portable 5.1 system which I salvaged from my old days. I have several TDA/TPA amps but this seemed better with a remote and other features.
Ok, I'm still not sure how to wire it with either one or two series/parallel Li-ion battery packs.
1. If I have one series/parallel 12 volt (using a step down dc to dc board which I have several) to 10.5 volts - do I make two leads from the one positive and place on the left and right connector prong which were connected to the transformer and place the the one negative lead from the battery pack to the center prong (the one black wire from the transformer)?
2. Or would it be better to have two battery packs and combine the negative leads from them and place on the center connector prong (black wire from transformer) and then each one pack's positive lead on the left prong and the other positive lead on the right prong?
Rayma - I don't understand how to wire your number 1 response.
Thanks
Good Suggestions about the inverter and car amp - I already have several of each but this build is for a portable 5.1 system which I salvaged from my old days. I have several TDA/TPA amps but this seemed better with a remote and other features.
Ok, I'm still not sure how to wire it with either one or two series/parallel Li-ion battery packs.
1. If I have one series/parallel 12 volt (using a step down dc to dc board which I have several) to 10.5 volts - do I make two leads from the one positive and place on the left and right connector prong which were connected to the transformer and place the the one negative lead from the battery pack to the center prong (the one black wire from the transformer)?
2. Or would it be better to have two battery packs and combine the negative leads from them and place on the center connector prong (black wire from transformer) and then each one pack's positive lead on the left prong and the other positive lead on the right prong?
Rayma - I don't understand how to wire your number 1 response.
Thanks
Wire the two batteries in series, with + to -. This common connection goes to the ground input.
The remaining free + terminal goes to the + input, and the remaining free - terminal goes to the - input.
It doesn't seem that my responses are going through as I did two of them to rayma and old and cranky. But I think I understand now what you'll mean about the wiring of the batteries. Is this correct?
It will not work with one battery or one battery pack. I need to have two. I will take the positive of pack# 1 and connected it to the left prong (blue from the disconnected transformer). I will take the negative of pack 1 and connect it to the positive Pack two and connect those to the center prong (black of transformer) and then take the negative of Pack two to the right prong.
Do I have it correct?
If so, I could not have done it without your help - Thanks
I will place a step down dc to dc board (I may need one for each pack - I have several from ebay) because 3 or 4 Li-ions will be more than 10.5 volts.
Thanks again,
It will not work with one battery or one battery pack. I need to have two. I will take the positive of pack# 1 and connected it to the left prong (blue from the disconnected transformer). I will take the negative of pack 1 and connect it to the positive Pack two and connect those to the center prong (black of transformer) and then take the negative of Pack two to the right prong.
Do I have it correct?
If so, I could not have done it without your help - Thanks
I will place a step down dc to dc board (I may need one for each pack - I have several from ebay) because 3 or 4 Li-ions will be more than 10.5 volts.
Thanks again,
Be careful!
You don't know what is in the circuit after the transformer! Check that first! If there is a full bridge rectifier, then the DC power is symmetrical, and you need 2 batteries, but if there are only 2 diodes, then probably the amp has asymmetric DC power rails (0 and 12 V). In the later case the second battery will not be loaded. Discover the rectifier first! The output power spec of the amp may help...
2.2A is the maximal current capability of the transformer. Current is not specified for most batteries, instead charge is specified in Ah, that is a different quantity. Only if you get battery with protection PCB, then current spec is important.
2.2A does NOT mean the amp actually consumes that much continuously, typically the consumption is a small fraction of this, and depends on the volume, load, and music signal also.
You don't know what is in the circuit after the transformer! Check that first! If there is a full bridge rectifier, then the DC power is symmetrical, and you need 2 batteries, but if there are only 2 diodes, then probably the amp has asymmetric DC power rails (0 and 12 V). In the later case the second battery will not be loaded. Discover the rectifier first! The output power spec of the amp may help...
2.2A is the maximal current capability of the transformer. Current is not specified for most batteries, instead charge is specified in Ah, that is a different quantity. Only if you get battery with protection PCB, then current spec is important.
2.2A does NOT mean the amp actually consumes that much continuously, typically the consumption is a small fraction of this, and depends on the volume, load, and music signal also.
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