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| I dont know how to wire this simple amp |
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| Zero999:
--- Quote from: Hextejas on September 03, 2018, 02:36:04 am --- --- Quote from: 6PTsocket on September 02, 2018, 11:50:28 pm --- --- Quote from: Hextejas on September 02, 2018, 09:22:37 pm ---Sheesh, such a simple problem to generate this much discussion. I bought these amps as throw away items, no tears if I burn them up. What I need it for is for testing a tuner to see if a 1khz signal is getting through. I wanted a very small footprint, easy connections to a very small footprint speaker. I have limited space on my work bench so this beast looks ideal. It sounds like I will need to give it more juice. I had not bothered reading the spec sheet, I just assumed that the 9v battery would be ample. Thanks. --- End quote --- Two 9 volt batteries should do the trick. If you run with a single power supply you will need a capacitor to couple a speaker to the amp or you will have half the DC voltage on the speaker. Not a good thing. It is amazing how all the ebay sellers have the same bad info. on their sites. I guess they all get them from the same wholesale source in China. Sent from my SM-G900V using Tapatalk --- End quote --- 6pt, thank you, and could you point me to some reading material that could explain why it would be " a bad thing " for me to wire my desktop 18v supply to this amp. Cause that is exactly what I was planning on doing. --- End quote --- It would work perfectly from a bench supply. There should be no need for any additional capacitor, as going by the photograph of the board, it's clearly designed for single supply operation, with that large capacitor next to the speaker terminals. |
| 6PTsocket:
I posted some bad info. Sorry. Pull up the data sheet for the TDA2030A from any of the companies that made it. There will be drawings of it running from a single supply like your 18 volts and with a split supply like two 9 volt batteries in series. With the 18 volt supply the minus terminal of the supply is ground. With two batteries in series, the tie point between them is ground. The ebay photo showed two grounds. One of them is actually the negative DC connection to the amplifier and the other is signal ground. In a single supply like your 18 volts they are tied together and you must use the 2200 mfd capacitor in one speaker lead or there will be 9 volts DC on the speaker along with the signal. In the split supply with 2 batteries, the signal ground is connected to the tie point between the batteries and no capacitor is needed. In that case we are using the tie point as ground and it is half way between +9 and -9 so it is zero and there is zero volts DC on the speaker. The input and the speaker use the tie point as the - or ground connection. I know it can be confusing. It is because you have two wiring options that there are two grounds on the ebay picture One goes to pin 3 on the chip. That is the one that is always tied to the most negative supply voltage. The other one is only tied to it when running a single supply with no center tap. --- Quote from: Hextejas on September 03, 2018, 02:36:04 am --- --- Quote from: 6PTsocket on September 02, 2018, 11:50:28 pm --- --- Quote from: Hextejas on September 02, 2018, 09:22:37 pm ---Sheesh, such a simple problem to generate this much discussion. I bought these amps as throw away items, no tears if I burn them up. What I need it for is for testing a tuner to see if a 1khz signal is getting through. I wanted a very small footprint, easy connections to a very small footprint speaker. I have limited space on my work bench so this beast looks ideal. It sounds like I will need to give it more juice. I had not bothered reading the spec sheet, I just assumed that the 9v battery would be ample. Thanks. --- End quote --- Two 9 volt batteries should do the trick. If you run with a single power supply you will need a capacitor to couple a speaker to the amp or you will have half the DC voltage on the speaker. Not a good thing. It is amazing how all the ebay sellers have the same bad info. on their sites. I guess they all get them from the same wholesale source in China. Sent from my SM-G900V using Tapatalk --- End quote --- 6pt, thank you, and could you point me to some reading material that could explain why it would be " a bad thing " for me to wire my desktop 18v supply to this amp. Cause that is exactly what I was planning on doing. --- End quote --- Sent from my SM-G900V using Tapatalk |
| Zero999:
I doubt two 9V batteries would do a good job at powering a TDA2030 amplifier. It certainly wouldn't work for long, at any decent power level. The internal resistance of a typical 9V battery is about 2.1 Ohms, when fresh, which would be 4.2 Ohms for two in series, so a load current of just 1A would cause the voltage to drop by 4.2V. What's worse is the internal resistance increases, as the battery discharges and at lower temperatures. The quiescent current taken by the TDA2030 is also quite high and is the sort of load a 9V battery is designed to power on its own. Using a large decoupling capacitor across the batteries will help to some degree, but this still isn't ideal. http://www.zeusbatteryproducts.com/wp-content/uploads/Zeus_9V.pdf A much larger battery is required, such as three 6V lantern batteries or 12 AA cells in series, to power the TDA2030 properly. |
| tooki:
--- Quote from: Hextejas on September 02, 2018, 09:22:37 pm ---Sheesh, such a simple problem to generate this much discussion. I bought these amps as throw away items, no tears if I burn them up. What I need it for is for testing a tuner to see if a 1khz signal is getting through. I wanted a very small footprint, easy connections to a very small footprint speaker. I have limited space on my work bench so this beast looks ideal. It sounds like I will need to give it more juice. I had not bothered reading the spec sheet, I just assumed that the 9v battery would be ample. Thanks. --- End quote --- If time isn’t of the essence, consider buying a cheap PAM8403 audio amp board from eBay. They’re class-D, run happily off 2.5-5V (so 3 AA batteries, or 3.3V or 5V from an existing circuit, are ideal; >5.5V will fry it), tiny, and cheap as dirt, even in the “fancy” versions with a built in volume pot. FWIW, you can’t be blamed for assuming it’d run off 9V, since the eBay listing clearly (yet demonstrably incorrectly) says 6-12V. |
| mariush:
If you want something super simple and cheap, you could always go for a PAM8301 ... mono amp, up to ~ 1.5w @ 8 ohm it's basically the chip and 3 ceramic capacitors... gives you around 1w at 8 ohm with ~ 90%efficiency: $0.54 at Digikey: https://www.digikey.com/product-detail/en/diodes-incorporated/PAM8301AAF/PAM8301AAFDICT-ND/8283873 Datasheet: https://www.diodes.com/assets/Datasheets/PAM8301.pdf Super easy to put on a prototyping board, just bend up the middle contacts and you solder the edge contacts on 0.1" proto board and solder a wire to the middle contacts or something like that... you can use it with power from usb or from 2-3 AA batteries. For a stereo amp, even easier to solder to a prototyping board as the contacts are 0.1" apart, you have PAM8403: https://www.digikey.com/product-detail/en/diodes-incorporated/PAM8403DR-H/PAM8403DR-HDICT-ND/8545994 Still cheap, at around $0.75 on Digikey ... though if you buy only a couple dollars worth from Digikey, they'll probably charge you something like 5-10$ for shipping. |
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