Hi! i'm new to the site and the world of building amplifier.
I successfully prototyped a J-FET pre-amplifier for my guitar amp I plan to use as my main rig.
for the power amp i'm trying to build a TDA2050 based circuit. i'm using the circuit from the datasheet and i'm using all the correct components, except when i power it i get no sound?
here's my theories for problems so far:
i have it set up on a breadboard just so i can get sound to see if the circuit works
i'm powering it with SLA batteries (temporarily) and the power supply I will build last, i'm only giving it 12v (I tried 24v with two in series to no avail) mostly because I know these are probably knock off chips from china and i'm afraid to run them at max voltage.
should I be using a different circuit? I only need a single channel and bare minimum for this project and i'm just trying to get sound from the amp at this point.
I've tried output from the pre-amp (also built a bit sketchy) and output music from my phone, both inputs are giving no output.
please let me know if i'm posting in the wrong place or you need more information. thanks!
https://www.google.com/search?q=tda2050+datasheet&safe=active&espv=2&biw=1366&bih=599&site=webhp&tbm=isch&imgil=b0ZqEWSkqFrIqM%253A%253B5kutd-s7Jh-HGM%253Bhttp%25253A%25252F%25252Fdiyaudioprojects.com%25252FChip%25252FDIY-TDA2050-Hi-Fi-Chip-Amplifier%25252F&source=iu&pf=m&fir=b0ZqEWSkqFrIqM%253A%252C5kutd-s7Jh-HGM%252C_&usg=__AbtnPTTWlS0d7cMYYK8WzkRtr78%3D&ved=0ahUKEwiS56Kl5drMAhXK24MKHS3EBeAQyjcIMg&ei=YL43V5K3Ecq3jwStiJeADg#imgrc=b0ZqEWSkqFrIqM%3A
Did you reference V+ and V- to ground individually? Or did you connect the V+ and V- to either end of a battery? The V+ and V- are separate power supplies, not the two ends of one.
i assumed a battery acted like a V+/V- supply. what would i have to do to make it that way?
you can use two batteries: connect + end of first battery to the Vs+ point on the schematic, - of the first battery to the ground, + side of the second battery to the ground and - of the second battery to V-. That way you get a +-12V power supply and everything should work just fine.
Like this:
(http://s32.postimg.org/j1ip3120h/bipolar.jpg) (http://postimg.org/image/j1ip3120h/)
Thanks alot! Ill try it out
I tried connecting the - of one battery and the + of another to ground and using the other terminals as a +/- supply like in the picture but it seems to be shorting the chip?? The speaker is popping and the chip is heating up
Then you'll have to triple check schematic against real world build.
You might have missed something.
A picture might help.
Agree,, either something is not connected that should be or something is connected that should not be.
It's very easy to miss wire a breadboard setup, especially when you are not familiar with electronics. 8|
If you are using batteries the Amp should be wired up like this picture and I'd be using a fuse on each supply rail. :-X If the batteries are large they can dump a lot of current instantly which would blow the chip in a blink if something was wired up wrong. :'(
Follow the 3 colours and make sure they go to the right pins.
And Yes a close up picture of what you have on the bench will help speed up the process. :dbtu:
Phil.
The tab of the TDA2050 is connected to the negative supply pin so the package must be insulated from the heatsink.
This is currently how i have it set up.
Pin 1: .1uf cap connected to the input and 22k resistor going to ground
Pin 2: 22k feedback resistor to pin 4 and 6.8k resistor going to 10uf cap to ground
Pin 3: just v- wire
Pin 4: 2.2 ohm resistor to .47uf cap to ground and speaker output
Pin5: just v+ wire
Chip seems to be shorting when i try to do the v+/v- supply trick with the batteries. Could it be a grounding issue? I have the breadboard grounded to the benchtop power supply i built but i dont know if thats actually connecting it to ground.
Please draw a schematic of what you actually built, even if in cheesy Paintshop, we do not rate artistic skills here.
Top it with a nice picture showing actual construction.
This is a simple circuit which "should" work.
That said, you might have already killed the chip because of some earlier misconnection :(
The exact datasheet schematic is what i seem to have built (obviously not somwhere). I bought 20 chips im not that worried about them blowing lol. I apologize for the photography. The green wire is v+ and the blue wire is v- (ran out of red and black recently) the red wire is going to an 8 ohm speaker and the yellow wires are just jumper cables.
Arrhh No !!!
Lesson one,,, NEVER Run these chips without a heat sink. :trouble :trouble :trouble
As Mr Fahey Has already noted, the chip is likely already fried but as you have many it's a lesson for you. :tu:
Can't quite make out the wiring but the heat sink is your first fix up job.
Phil.
I thought those tda's have long been gone and out of production? Where could they still be located?
Even if im just trying to get sound out of it as a test i need a heatsink? And the question about production, im pretty sure these are knockoffs from china i ordered them at amazon.
Yes, those chipamps do run very hot and needs heatsink even without load. :)
Or you'll fry it in seconds
Would you ever run a car engine - just for a second to see if it works - with no coolant in it? Or no oil? Like he just said, it can overheat in seconds.
What do you mean by "shorts out" the IC?
Im assuming thats whats happening because im getting no sound and really rapid heat build up
When the chips go bad, you can usually find an internal short by Ohming between the V+ or V- pins to the output pin. Measure an unused chip to establish what a normal reading is. On a good chip the reading may change if you reverse the red and black meter leads.
Thanks. I checked my chips and i lt appears i havnt blown any (yet) but i am still not sure whats wrong with my circuit. Should i try using a pc power supply that i know is +/- 12v?
As long as the supplies are connected to ground at one end, and the proper + and - polarities are connected to the circuit, it doesn;t matter what type of power supply you use. 12v is 12v, the transistors don;t know any different.
And get the IC on a heat sink, without that, it will never work.
and make sure you made the right connections. I've tried powering up an LM1875 amp before and wondered why it won't work. After just 2 seconds, i turned off the power only to find that I made the wrong connections for my + and -
I was lucky no component was damaged. ;)
After that, I decided never to work in my electronic projects again when my mind or body is not in good condition. I was sleepy then coz I don't want to leave the project unfinished. :P