Author Topic: I dont know how to wire this simple amp  (Read 6493 times)

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Offline HextejasTopic starter

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I dont know how to wire this simple amp
« on: August 31, 2018, 07:17:22 pm »
I am trying to hook my signal generator to a cheap. class D mono, amplifier.
The amp has 4 inputs.
1. VCC
2. In
3 Gnd
4 Gnd

and I hooked them like this:
1) VCC = +9v
2) In = 1khz test tone + lead
3) Gnd = -9v
4) Gnd = 1khz - lead

Is this correct and how come I cant hear anything ?
 

Offline BergRD

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Re: I dont know how to wire this simple amp
« Reply #1 on: August 31, 2018, 07:21:21 pm »
Silly question here, so please ignore, but have you hooked up the output to speaker(s)? 

Just covering the bases here and KISS theory.
 

Offline HextejasTopic starter

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Re: I dont know how to wire this simple amp
« Reply #2 on: August 31, 2018, 07:34:34 pm »
Yes I did and not a silly question. The thing is that I had another el cheapo stereo amp and it was working until it stopped. Dont know why, I prolly fried something on it.
I swapped it out for this mono beauty. but no sound.
 

Offline P_Doped

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Re: I dont know how to wire this simple amp
« Reply #3 on: August 31, 2018, 07:47:36 pm »
1) Is the - terminal of your signal source floating or is it connected to earth ground?

Just wondering since you have both a -9V supply and the - terminal connected to the same potential on the board.

2) Do you know if the board can take a total of 18V between the VCC/Gnd pins?

3) If you measure the voltage between the VCC & Gnd pins, do you see 18V?

4) Do your 9V supplies have the ability to display their output current (could be 9V batteries, for all I know)?  If so, what type of current are they showing?

5) What are the electrical characteristics of the speaker hooked up to the board?
 

Offline HextejasTopic starter

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Re: I dont know how to wire this simple amp
« Reply #4 on: August 31, 2018, 08:04:04 pm »
1) Is the - terminal of your signal source floating or is it connected to earth ground?

Just wondering since you have both a -9V supply and the - terminal connected to the same potential on the board.

2) Do you know if the board can take a total of 18V between the VCC/Gnd pins?

3) If you measure the voltage between the VCC & Gnd pins, do you see 18V?

4) Do your 9V supplies have the ability to display their output current (could be 9V batteries, for all I know)?  If so, what type of current are they showing?

5) What are the electrical characteristics of the speaker hooked up to the board?

1) Is the - terminal of your signal source floating or is it connected to earth ground?
Its connected to one of the "Gnd" marked connections on the board.

Just wondering since you have both a -9V supply and the - terminal connected to the same potential on the board.

2) Do you know if the board can take a total of 18V between the VCC/Gnd pins?
Dont know

3) If you measure the voltage between the VCC & Gnd pins, do you see 18V?
I will check

4) Do your 9V supplies have the ability to display their output current (could be 9V batteries, for all I know)?  If so, what type of current are they showing?
It is a  9v battery

5) What are the electrical characteristics of the speaker hooked up to the board?
[/quote]
I think that they are an 8ohm desktop style speaker, but I will look more closely tomorrow.
 

Offline glarsson

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Re: I dont know how to wire this simple amp
« Reply #5 on: August 31, 2018, 08:05:41 pm »
I read the description as one 9V battery with plus to Vcc and minus to GND.
 

Offline Zero999

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Re: I dont know how to wire this simple amp
« Reply #6 on: August 31, 2018, 08:15:41 pm »
I read the description as one 9V battery with plus to Vcc and minus to GND.

Yes, going from the original poster's description, It's not a dual power supply, but a single 9V battery. By convention, saying +/-9V power implies a bipolar PSU, with a  total voltage of 18V and a centre tap in the middle, which is the 0V. This can confuse beginners who''ll take a 9V battery and call one side +9V and the other -9V, which is incorrect.

I am trying to hook my signal generator to a cheap. class D mono, amplifier.
The amp has 4 inputs.
1. VCC
2. In
3 Gnd
4 Gnd

and I hooked them like this:
1) VCC = +9v
2) In = 1khz test tone + lead
3) Gnd = -9v
4) Gnd = 1khz - lead

Is this correct and how come I cant hear anything ?
So you have a single 9V battery, giving a total supply voltage of 9V. In this case the correct terminology is 9V and 0V or ground, as +/-9V implies a bipolar 9V supply, i.e. two 9V batteries in series, with the ground or 0V terminal being where the two batteries join.

Are you sure the battery is good? Have you measured the battery voltage, with the amplifier connected to it?

I doubt a small 9V battery will be able to power this amplifier for long, if at all. A power supply with a higher current capability i.e. lower internal resistance is required to power this amplifier properly.
 

Offline P_Doped

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Re: I dont know how to wire this simple amp
« Reply #7 on: August 31, 2018, 08:50:49 pm »
Okay, not 2 9V supplies but 1.  I understand now.

I agree with Hero999, a single 9V battery has a large internal resistance of 1 - 2 ohms.  It could be that as soon as the device on the board starts to consume reasonable currents, maybe at startup or soon after the audio is driving the speaker, that 9V battery doesn't look so 9V anymore and the chip stops and restarts (many chips have under voltage detection which gates their operation if the supply is below a defined minimum).

If you have an oscilloscope, watching the across VCC/Gnd would tell you if the battery is holding up.  I'm guessing you don't have such a device at hand.

You could also try putting together your own "9V" with 6 AA batteries in series and seeing if that works.

 

Offline Audioguru

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Re: I dont know how to wire this simple amp
« Reply #8 on: September 01, 2018, 12:49:08 am »
Please post a link to the amplifier and the part number of its IC.
 

Offline gedong

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Re: I dont know how to wire this simple amp
« Reply #9 on: September 01, 2018, 01:04:45 am »
from the OP image it's unlikely to be Class D amp. more like chip amp

quick googling its seems like single supply version of TDA2030/50
« Last Edit: September 01, 2018, 01:10:53 am by gedong »
 

Offline Brumby

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Re: I dont know how to wire this simple amp
« Reply #10 on: September 01, 2018, 01:36:06 am »
Have you checked the speaker?

Simple field test: Use a 1.5V battery and a couple of wires connected to the speaker terminals.  Hold one wire to one end of the battery and briefly tap the other wire to the other end of the battery (polarity not important).  You should hear a pop and/or crackle.

The actual sound doesn't matter - just whenever the circuit is completed/broken you get some sort of noise at a clearly audible level, the speaker is good.  This is a simple test that proves continuity and cone movement.

Don't have the battery connected for anything more than a fraction of a second.  A constant DC voltage will prove nothing as the cone will be held in one position and sound is only created with cone movement.  Also, if you have a low impedance speaker with a low power rating, connecting a battery for too long may heat up the voice coil.  In those cases, just brush the second wire over the second battery terminal.

A multimeter continuity test will show if there is a circuit, but it may not offer enough current for an audible response.  If the speaker cone is jammed, then it may not produce any sound, even though the voice coil is intact.
« Last Edit: September 01, 2018, 01:42:30 am by Brumby »
 

Offline rdl

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Re: I dont know how to wire this simple amp
« Reply #11 on: September 01, 2018, 04:34:36 am »
Pretty much every seller of electronic doodads from China offers those amplifier modules.

https://www.ebay.com/itm/TDA2030A-Audio-Amplifier-Module-Power-Amplifier-Board-AMP-6-12V-1-18W/192163691131
 

Offline HextejasTopic starter

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Re: I dont know how to wire this simple amp
« Reply #12 on: September 01, 2018, 11:27:33 am »
Pretty much every seller of electronic doodads from China offers those amplifier modules.

https://www.ebay.com/itm/TDA2030A-Audio-Amplifier-Module-Power-Amplifier-Board-AMP-6-12V-1-18W/192163691131
That's the one I have. Thank you rdl. Now back to my questions. The 9v is a battery and I have a 1kHz tone at 5v coming from a signal generator. The battery has a pos and a neg terminal. And so does the generator. So what wire goes to which of the 4 connections ?
Maybe there is not enough juice in the 9v to be able to push this speaker. It worked ok with the prior amp,, although it was a different device. A cheap Chinese stereo amp.
 

Offline StillTrying

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Re: I dont know how to wire this simple amp
« Reply #13 on: September 01, 2018, 12:04:33 pm »
The minimum voltage for the TDA2030A is 12V or +/-6V, and 50mA quiescent current, so you'll have to try it with a bit more voltage and current.

The ebay link looks like someone has thought +/- 6V is the same as 6V - 12V.

Are the 2 GNDs pins on the board actually connected together.
.  That took much longer than I thought it would.
 

Offline Zero999

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Re: I dont know how to wire this simple amp
« Reply #14 on: September 01, 2018, 12:50:41 pm »
As mentioned above, the TDA2030 is not a class D amplifier, but a class AB amplifier. It is also completely unsuitable for operation at 9V. If you need it to run off a 9V battery, your best option is to return it, get a refund and buy an amplifier which really will work off 9V.
https://www.ebay.com/itm/DC-3V-9V-TDA2822M-Mini-Mono-Audio-Single-Power-Volume-2W-Amplifier-Board-Module/252840104297?epid=722098777&hash=item3ade71d169:g:75UAAOSw4CFY33PK

If you want to keep your this amplifier, then you need a much higher power supply voltage. Although the TDA2030 will work off 12V, it still isn't optimal and at 12V will probably only give an output power of 2W, into a 4Ω speaker or 1W into an 8Ω speaker. A 24V power supply is ideal. Two 12V 7Ah sealed lead acid batteries and a 5A fuse would be perfect for powering the TRDA2030.
 

Offline Audioguru

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Re: I dont know how to wire this simple amp
« Reply #15 on: September 01, 2018, 01:22:44 pm »
Why do people buy cheap Chinese junk from ebay who knows no Engrish and knows no elekronics.
 

Offline 6PTsocket

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Re: I dont know how to wire this simple amp
« Reply #16 on: September 01, 2018, 01:50:06 pm »
1) Is the - terminal of your signal source floating or is it connected to earth ground?

Just wondering since you have both a -9V supply and the - terminal connected to the same potential on the board.

2) Do you know if the board can take a total of 18V between the VCC/Gnd pins?

3) If you measure the voltage between the VCC & Gnd pins, do you see 18V?

4) Do your 9V supplies have the ability to display their output current (could be 9V batteries, for all I know)?  If so, what type of current are they showing?

5) What are the electrical characteristics of the speaker hooked up to the board?
From the OP's description and the picture, it is a single ended 9 volt supply There is no mention of a  + and - supply, unless I missed something or he left it out. Maybe that is the problem

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Offline Zero999

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Re: I dont know how to wire this simple amp
« Reply #17 on: September 01, 2018, 01:54:19 pm »
Why do people buy cheap Chinese junk from ebay who knows no Engrish and knows no elekronics.
You appear to have forgotten that this is the beginners section.

If someone doesn't have much electronics knowledge then how are they supposed to judge the knowledge of the seller and know what to buy?

Yes, there are plenty of crappy products on ebay, but there are some very good ones too.
« Last Edit: September 02, 2018, 09:15:56 am by Hero999 »
 
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Offline 6PTsocket

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Re: I dont know how to wire this simple amp
« Reply #18 on: September 02, 2018, 02:29:06 pm »
I just looked at the TDA 2030A data sheet and there is nothing to suggest that it was ever intended to run with a single ended supply voltage. The specs are +or- 6 to + or - 22 volts. What was misread as two grounds were the actual ground and the minus power supply connection. A pair of 9 volt batteries would work for as long as they lasted, which might not be much.

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Offline mariush

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Re: I dont know how to wire this simple amp
« Reply #19 on: September 02, 2018, 02:59:46 pm »
TDA2030  (and the others in the series, like the much better TDA2050 for example) can be run with split power supply or with a single power supply - the circuit is slightly different but not by much.

See the attached datasheet, at page 8, you will see example circuits for either split power supply (where you would use at least +6v and -6v supplies to power the board), and an example circuit which can run with a simpler supply of just +12v or more.
The chip requires a minimum of 12v to work (or  -6v supply AND 6v supply  for a total of 12v difference)  and can work with up to 36v ( or -18v AND +18v in split power supply mode) - see page 3 in the datasheet where these numbers are shown.

The efficiency of this kind of amplifier (class AB and average performance wise) is at around 60% , so it needs a lot of voltage to output a reasonable amount of sound, and it also heats (hence the heatsinks on it).
You can look on page 5 of the datasheet and you'll see there figure 4 and figure 5 .. output power vs supply voltage ... you should only care about figure 4, where the drawing is for  distortion of 0.5% ... the other figure is for distortion up to 10% which is not great for music (but if you want to make an amplifier for announcements in a train station for example you wouldn't care about music and this would be acceptable)
So back to figure 4, you can see there that 4 ohm speakers are easier for the amplifier and it will output more sound power with 4 ohm speakers.  So you can see there they don't even calculate how the chip would work with 12v ( or -6v and 6v) , they start right from +/- 8v (or 16v dc) ... at that point you can see that the chip can output just a bit over 2w on a 8 ohm speaker, and just around 4 watts with a 4 ohm speaker.

So basically, you need a much higher power supply to use this amplifier, my suggestion would be using one of those laptop adapters that output anything between 16.5v and 19v, they should be super easy to find.
Alternatively, you should look for a 15v..24v AC transformer and use a bridge rectifier and a capacitor to convert this 15v..24v AC to around 20..32v DC.  As long as the voltage will be below the maximum this chip supports  (and below the input capacitor's voltage rating on the board you have .

So also look at the voltage rating on the capacitors on your board and if for example it says 25v on the capacitor, then you shouldn't use more than around 24v at the input, unless you replace the capacitor with one rated for higher voltage (35v or 50v rating)

For testing that the board actually works, the easiest for you would probably be to connect two 9v batteries in series.  Though note that 9v batteries aren't really designed to give a lot of energy to devices, so the amplifier chip may try to take too much out of the batteries and then the voltage on the batteries will drop quickly.


I'm attaching the tda2030 datasheet below:
« Last Edit: September 02, 2018, 03:02:14 pm by mariush »
 

Offline 6PTsocket

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Re: I dont know how to wire this simple amp
« Reply #20 on: September 02, 2018, 04:16:24 pm »
OOPS !! I stand corrected. I never went through all the data sheets. It will run from a single or split power supply. Is one  preferable? It is not a whole lot more work to build a split supply.
I just looked at the TDA 2030A data sheet and there is nothing to suggest that it was ever intended to run with a single ended supply voltage. The specs are +or- 6 to + or - 22 volts. What was misread as two grounds were the actual ground and the minus power supply connection. A pair of 9 volt batteries would work for as long as they lasted, which might not be much.

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Offline mariush

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Re: I dont know how to wire this simple amp
« Reply #21 on: September 02, 2018, 04:40:08 pm »
OOPS !! I stand corrected. I never went through all the data sheets. It will run from a single or split power supply. Is one  preferable? It is not a whole lot more work to build a split supply.

Split power supplies save you one big capacitor (in series with by the speaker with single power supply).Also makes easier to do bridge amps (see datasheet for example), to use 2 x tda2030 with one speaker to get more power.

anyway, for experiments, it may make more sense to buy some tda2050 chips and use example circuit from datasheet or google and you'll find complete schematics on dyi sites.
from memory tda2050 works from 10v and up (or -5v and 5v) so it would be very easy to use with a 12v atx power supply or a laptop adapter
 

Offline 6PTsocket

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Re: I dont know how to wire this simple amp
« Reply #22 on: September 02, 2018, 07:13:56 pm »
OOPS !! I stand corrected. I never went through all the data sheets. It will run from a single or split power supply. Is one  preferable? It is not a whole lot more work to build a split supply.

Split power supplies save you one big capacitor (in series with by the speaker with single power supply).Also makes easier to do bridge amps (see datasheet for example), to use 2 x tda2030 with one speaker to get more power.

anyway, for experiments, it may make more sense to buy some tda2050 chips and use example circuit from datasheet or google and you'll find complete schematics on dyi sites.
from memory tda2050 works from 10v and up (or -5v and 5v) so it would be very easy to use with a 12v atx power supply or a laptop adapter
There is a little speaker protection with a cap against power supply imbalance failure damage  but I never had any problems with my old Sony 110W per channel direct coupled amp. I would go with a split supply.

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Offline Audioguru

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Re: I dont know how to wire this simple amp
« Reply #23 on: September 02, 2018, 07:17:03 pm »
it may make more sense to buy some tda2050 chips..... so it would be very easy to use with a 12v atx power supply or a laptop adapter
The TDA2050 is obsolete and is not made anymore. Digikey has none.
With a 12V supply its output power was only 2W if the speaker was 4 ohms or 8 ohms.
 

Offline Zero999

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Re: I dont know how to wire this simple amp
« Reply #24 on: September 02, 2018, 07:32:59 pm »
it may make more sense to buy some tda2050 chips..... so it would be very easy to use with a 12v atx power supply or a laptop adapter
The TDA2050 is obsolete and is not made anymore. Digikey has none.
With a 12V supply its output power was only 2W if the speaker was 4 ohms or 8 ohms.
TDA2050 amplifier modules are still widely available on ebad, probably using new old stock parts, more than fakes.  The LM1875 is a suitable replacement, according to Google.

Yes, an IC designed for 12V operation should be used, perhaps the LM4940 can be bridged to give around 4W into an 8Ω load, with reasonably low distortion?

http://www.ti.com/lit/ds/symlink/lm4940.pdf
 


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