Hello there 🙂
Is there any way to identify the ratings of a power transformer by the product number in the service manual of a Sony power amp? I try to make a quick search through the internet but nothing found.
Thanks you 🙂
Is there any way to identify the ratings of a power transformer by the product number in the service manual of a Sony power amp? I try to make a quick search through the internet but nothing found.
Thanks you 🙂
The label on the backside, showing voltage and power, may give you a clue because pretty much all electronics inside are supplied with this very transformer.
Keep a safe margin too.
Keep a safe margin too.
Well the sticker says 220-230v ac - 300w how can I discover with this informations about the ratings? Sorry if the question is silly I’m new to this, thanks you 🙂
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I presume you want to know the transformers VA rating and current output.
Service manuals don't usually give this but you can estimate it as follows:
The label indicates the amplifer has a maximum power draw of 300w.
A transformer that can deliver 300 watts will have a VA rating about 10% higher, so about 330 VA.
To estimate the current rating just divide the power - 300w by the total voltage for the main secondary winding(s) that run the amps DC power supply.
For example, if the transformer has a 70 VAC center tapped winding, then the available curent is 300W / 70V = 4.3A
If the schematic doesn't show the winding voltage, you can just measure it, or calculate it from the DC rail voltages, which should be on the schematic.
For a simple unregulated DC power supply, the winding AC voltage is estimated as Total DC Rail Voltage / 1.4.
For example the 70 VAC CT transformer above would make a DC power supply with about +/- 50 VDC rails or 100 VDC total.
Again, these are approximate results, but should be close enough to give a good idea of what you're dealing with.
Service manuals don't usually give this but you can estimate it as follows:
The label indicates the amplifer has a maximum power draw of 300w.
A transformer that can deliver 300 watts will have a VA rating about 10% higher, so about 330 VA.
To estimate the current rating just divide the power - 300w by the total voltage for the main secondary winding(s) that run the amps DC power supply.
For example, if the transformer has a 70 VAC center tapped winding, then the available curent is 300W / 70V = 4.3A
If the schematic doesn't show the winding voltage, you can just measure it, or calculate it from the DC rail voltages, which should be on the schematic.
For a simple unregulated DC power supply, the winding AC voltage is estimated as Total DC Rail Voltage / 1.4.
For example the 70 VAC CT transformer above would make a DC power supply with about +/- 50 VDC rails or 100 VDC total.
Again, these are approximate results, but should be close enough to give a good idea of what you're dealing with.
Finally someone would know I thought 🙂 Have a few very nice Sony transformers but type numbers don't seem to have anything to do with power or voltages/current.
Time to refresh knowledge regarding the iron & copper tests. Sony had its transformers mainly made by either Tamura or Kitamura Kiden. They usually are overdimensioned too (the older ones). Often with multiple windings/secondaries too. Good stuff.
Time to refresh knowledge regarding the iron & copper tests. Sony had its transformers mainly made by either Tamura or Kitamura Kiden. They usually are overdimensioned too (the older ones). Often with multiple windings/secondaries too. Good stuff.
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These transformers usually have main and auxiliary secondary windings. For the main windings, (if the power of the transformer is known) the current can be determined quite accurately, but for the auxiliary windings, it is difficult. I don't know if it's worth contacting Sony with that product number?
thanks for your answers, well the amp was just some few parts that have in my hands because was a donor unit to fix other amps so one of the parts that missing was the transformer so I don’t have physical access so I can find any ratings or something and I was thinking to find an aftermarket one with the same ratings to replace it
If you find out the data, the custom transformer can always be wound. Of course, it will happen that it does not physically match the old one, so installation may not be possible in some cases.
Misunderstood the question because of phrasing. If you need a replacement transformer for an existing amplifier:
1. You will need to know rectified and filtered voltages to the amplifier.
2. You will need to know if the transformer has extra windings for preamp, relays etc. Check if this can be solved by using an extra small transformer.
3. Current/power can be determined approximately by the transformer size. Best is to "gamble" by exxagerating and choose the larger one if that one fits physically. Larger is no problem, smaller is.
4. For adequate help to solve a specific issue we need to know specific information. Like amplifier brand and type number. Otherwise the "car for sale, color red" syndrome will turn up. Possibly it is mentioned in the service manual or possibly a member has that same amplifier.
1. You will need to know rectified and filtered voltages to the amplifier.
2. You will need to know if the transformer has extra windings for preamp, relays etc. Check if this can be solved by using an extra small transformer.
3. Current/power can be determined approximately by the transformer size. Best is to "gamble" by exxagerating and choose the larger one if that one fits physically. Larger is no problem, smaller is.
4. For adequate help to solve a specific issue we need to know specific information. Like amplifier brand and type number. Otherwise the "car for sale, color red" syndrome will turn up. Possibly it is mentioned in the service manual or possibly a member has that same amplifier.
If only the box and some parts are left of that amplifier, it is a pharaoh's job to restore it to working condition. It is much easier to make something else and put it inside, use the box and heatsinks if they are saved. An SMPS supply and D class amplifier can be made, like Lego blocks.
Finally, if there is a valid schematic and PCB is saved, it can be determined what kind of transformer is needed for that amplifier.
Finally, if there is a valid schematic and PCB is saved, it can be determined what kind of transformer is needed for that amplifier.
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Well it’s a class a power amp (I guess “signature” line or something) from Sony model number ta-nr1 I don’t even had the chassis for this amp I only have a few boards like power amplification board and and some others like temp. Meter board which as I see there as a temp meter in the front of the amp that connects to it, so I guess that would be a good idea to find the missing parts or alternatives and put them into a chassis just for getting start and learn about electronics from this “mini project” 🙂
https://circuit-zone.com/pdf/Sony_TA-NR1.pdf
The Specifications of SONY TA-NR1 and service manual above should provide everything you want to know.
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2 x 35...38V 750 VA weighing a whopping 14 kg as is clearly stated in the link by crisng. Too bad but it has 1 extra winding for the VAS power supply. Technically a fine choice, challenge for you. Can be solved with an extra small 80VA 2 x 35V (in series) transformer. Surprisingly it has no middle point connection.
Not a pharaohs job, a pharaoh workers job costing a pyramid.
Not a pharaohs job, a pharaoh workers job costing a pyramid.
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