| Electronics > Beginners |
| I dont know how to wire this simple amp |
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| Audioguru:
Why do people buy cheap Chinese junk from ebay who knows no Engrish and knows no elekronics. |
| 6PTsocket:
--- Quote from: P_Doped 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? --- End quote --- 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 Sent from my SM-G900V using Tapatalk |
| Zero999:
--- Quote from: Audioguru 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. --- End quote --- 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. |
| 6PTsocket:
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. Sent from my SM-G900V using Tapatalk |
| mariush:
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: |
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