Another amp

[chemelec]

I Believe that is Correct.

 

[chemelec]

It is NOT Possible to post a Resistance Value, as This adjustment "corrects" for various Tollerances in Transistors and other parts. It will change from one to the next.

A PCB Layout is now Available at: http://www3.telus.net/chemelec/Projects/Projects.htm

Look at the PCB ...., Article

My board has Meter Connection Pads for a Meter to set the 1.8 Ma. After Set, Put a Jumper in there.

 

[pichichus]

Current of the relay

I have made some calculations and i want that you confirm my suspects. The current that the relay may support is I^2=P/R so if whe use speakers of 4 ohms the aprox max current for the relay is 8.6 Amps? So we need a relay of 8 amps?

Another little question, what width of wire do you use to drive 6-8 amps in the pcb?

Thks a lot, whising to know early about it

Pichichus

 

[chemelec]

The Circuit Board Doesn't have to handle the Output Speaker Current, as the Output Transistors are mounted on Seperate Heatsinks.

And the power supply rails (+ & - volts) are Very short traces of 2 ounce copper. they will easily handle the supply current.

Gary

 

[pichichus]

Yes the output stage is mounted outside the pcb, but this dc protection contens the relay. I will use one for pcb, so i've to cross the relay throught pcb. I think that the courrent that the switch of the pcb suports is aproximately maximum 8 amps. Isn't?
The width for 8 amps must be too large... so i'm considering to mount out the realy.
But, this 8 amps, are well calculated? can you help me? Use I a relay for 8 amps?

Thks

 

[chemelec]

I haven't actually built this amp and I didn't look that closely at the Relay protection circuit, But it Does NOT Mount on the main circuit board. It is a Seperate circuit.

If you want More Help, Email me Directly at: chemelec@hotmail.com

Put "Electronic M250" in the "Subject Line".

It would also help me to help you if you send me a picture of the Schematic of this relay circuit and how it connects to the amp.

Than I can probably help you a lot more. I could maybe also do a board for the relay.

Take care..........Gary

 

[moutzy]

Project

I'm currently going to school at SAIT in Calgary, AB. I'm thinking of building this amp for my final project.
Has anyone gone to SAIT and built this amp for their final project and if you have how did it work for you?
Did you have enough time to complete it?
Could you find all the necessary parts easily?

 

[reign]

hi!! i just want to ask if this amplifier could drive until 6 hours continous duty?how does it sounds when it comes to bass ?

 

[bigpanda]

For guys who have built the speaker protection unit :

I built the protection unit for another amp but this thing is behaving really crazy. The contact closed with no delay at all. When a 3V dc is applied to where the speaker is suppose to go, it won't trip. Can anyone have come comment on this ? It's now lying peacefully on top of my monitor.

 

[Dragance007]

You did not asemble the parts correctly for shure. My prototype is working just fine.

 

[moutzy]

Does anyone know any good electronic parts suppliers in Canada or USA. I currently looking for the best place to buy all the parts necessary to build this amp from an online supplier.
Preferably a Canadian supplier but any will do.

 

[Dragance007]

Chemelec, i have one question...
This is part of your pcb design. Is't the Colector of T8 driver suposed to be on the + rail ?
i am about to make two of this boards and i belive this is a mistake

 

[Dragance007]

it can be corected like this

 

[chemelec]

I have Misplaced the Origional Schematic. If you send it to me, I'll correct the error if there is one.

But I Also Don't see any difference between your two Posts.

chemelec@hotmail.com
PLEASE Put the Words "Electronic M250" In the Subject Line.

Take care..........Gary

 

[chemelec]

I Found the Schematic and Have Now Corrected the PCB Error on my website.

Take care..........Gary

 

[Dragance007]

this is the component side with corrected error

 

[Dragance007]

this is the copper side...not so well done
many thanks to chemelec for this pcb design
see ya

 

[chemelec]

Hi Dragance007, Did you put T8 and T9 on the Board?
They should show on the Parts Side where you have the Heat Sinks, Or did I do them Backwards?

How About This Parts Overlay, From your Picture.

I also Edited that Jumper and Fixed it.

Take care.............Gary (Chemelec)

 

[Dragance007]

Maybe not this week, but very soon i will finish the boards and report how it works at full power.
I think the pcboard is now OK.
Stay well everyone....bye..

 

[chemelec]

Dragance007, I have 4 of these Origional boards, with that Error.

Since this error is Fairly Easily Corrected and Because of your Feedback on this, If you want Two of these Boards, I will send them to you for Totally Free, including the postage cost.

Once I know if you Do or Don't want them, I will than Give away the remaining 2 or 4 boards to one or two lucky persons, ALSO TOTALLY FREE.

(FURTHER DETAILS WILL BE COMING IN THE NEAR FUTURE.:

(NOTE: I Especially Designed, Etched and Drilled these 4 boards for another Person, But he Never came through with the money.
These kind of guys "CHEESE ME OFF", But on the other hand, they are Useable Circuit Boards and I hate to see them go to waste.)

Take care..........Gary