hey everyone,
i am doing an electronics project finvolving amplifiers for school. But i came across a few problems. I looked all over the web but i wasnt able to find a decent amplifer circuit. I need about three amps and one or two preamps for my project. It would be wonderfull and i would be sooo happy if some of you guys could help. Thanks in advance
thomas

 

You don't give any specifications?.

There are hundreds available on the net, try looking at http://www.discovercircuits.com/list.htm for a good start.

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i looked on discovercircuits and redcircuits but they for some reason didnt really work out. Do you know of any that have a rather simple design, and use between 5 and 25 Watt. It would also be nice if they ran on a Voltage of 5 or 12. the amplifier doesnt need to be stereo, mono is perfectly fine. Would it be possible for you to help me now? Thanks

 

You need to decide what your exact requirements are?, and what your limitations are! - only certain power levels are available from your specified voltages (without adding a LOT of complications!).

With a 12V supply a 'normal' amplifier can output roughly 4W into 4 ohms, or 2W into 8 ohms - at 5V the output levels are greatly smaller!.

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in this case, an amp with 12V and 4Watt into 4Ohm would be perfectly fine.

 

look, i am rather new to electronics but i am very interested in it and i hope to learn and find out much more about it. Unfortunately i dont really know how many Watts and so on would really fit my needs for my school project. I just need a few different amplifiers that will work, and have a rather simple design. when i looked at discovercircuits.com, i wasnt exactly sure which one to use and so on. I am rather frustrated because i cant really figure out how to design one myself, and im not really able to find one that i am sure that i will manage to build it. so please help me and just post some amp design that works and isnt too complicated thanks
thomas

 

This one, from discover circuits, looks pretty easy http://web.telia.com/~u85920178/use/afamp-4w.htm. You could simplify things a lot by using an IC amplifier - the 4W 12V figure I mentioned is a standard car radio amplifier level, and there are many suitable IC's used in them.

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thank you soooo much!!! do you by any chance know of any circuit diagrams of some ic amps or the standard 12V 4W car amps? The problem is that i need more than one amp for the project. thanks for the help

 

You might try looking for datasheets for the TDA2002 and TDA2003 series, the TDA2004 and TDA2005 will also work off 12V as well.

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once again thanks aloooot! right now i am looking through different examples of the amps you mentioned. Is there any way that i can check the diagram if it works or not? Also, is there anything that i need to whatch out for when i build the amp?
thomas

 

Generally the datasheets tell you everything you need to know, some even give PCB layouts - so there shouldn't be any problems.

__________________
PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

 

Eh Thomas,
Below is a pic of a 20 watt amp desingned by siliconchip and it's called the schollies amp. I think it's a great kit to get started into amp projects and best of all the kit is under $20. This kit is available from www.Altronics.com.au and just quote K5116 in the search box

Cheers Bryan1

Attached Images

amp_431.gif (39.8 KB, 1429 views)

 

thanks brian, but the problem is that i live in Vienna, Austria and the amp needs to be self build. ill try to find a shematic for the amp you mentioned, or any other usable one. any ideas?
thomas

 

thanks brian, but the problem is that i live in Vienna, Austria and the amp needs to be self build. ill try to find a shematic for the amp you mentioned, or any other usable one. any ideas?
thomas

 

Hiya Thomas,
Below is the schematic of the schoolies amp and a suitable power supply. If you like I can send you the circuit board pics along with a description of the circuit via pm.

Hope this helps

Cheers Bryan1

Attached Images

	power_supply_376.gif (43.0 KB, 1365 views)
	amp_schematic.gif (58.3 KB, 1368 views)