UGS adventures

[dsdjoy]

Originally Posted by Manu

Did you measure the voltage at the output of the PSU (before first reg)?
Manu

Thanks Manu ! Voltage behind rectifier bridge is 33.9 Volts without load.

Should be ok for ST Microelectronics regulators with spec: max. 35 Volts input. I had that "ST" regulator in the board for one year before the amp stopped to work. I will put a new one of the same type in as next step.

Regarding power consumption:

Layout is: Transformer 24V AC 8VA => 7809 regulator => uC board with 7805 regulator => Atmel CPU & VFD Display

Atmel Atmega64 specification says consumption between 200 to 400mAmps.
Newhaven VFD M0220MD-202MDAR1-3 consumes 290 to 435 mAmps.
Total: 490 - 835 mAmps *5Volts = 2.5 to 4.2 Watt.

On top of that comes dissipation of the 7809:
( 33Vin - 9Vout) * 490mAmp = 11.8 Watt
( 33Vin - 9Vout ) * 835 mAmp = 20 Watt

Total: 14.3 to 24.2 Watts power draw, clearly exceeding the 8VA per side rating of the transformer.

So, maybe the transformer is the root cause of the problem.
I noticed also in past year the power supply got quite warm when in operation....

I wonder why not many of the other UGS builders in France have same problems....many builds were made according to same BOM / Layout.
What kind of Display and central Transformer do you use in your UGS ?

[Manu]

Originally Posted by dsdjoy

What kind of Display and central Transformer do you use in your UGS ?

I use the so called " as blind as a bat" big blue Christallfontz display
Which is not so power demanding ...
And on the PSU side : 12V relays to avoid the reg problem ...
(the first one was running 24V relays without problems though)
Trafo is 16VA (ERA EI54 or block) from Reichelt if I recall right (I am not at home right now and can't check)

Hope you solved your problem ..

Manu

[Stealth]

Hi all!
Does anybody have crystalfontz display (CFAH2002L) they would like to sell?
Thanks

[dsdjoy]

Originally Posted by Stealth

Hi all!
Does anybody have crystalfontz display (CFAH2002L) they would like to sell?
Thanks

I got mine here for 31,80 EURO: www.lcd-store.de

[Stealth]

dsdjoy
thanks a lot!

[safety fast]

Hello,

I'm lookink for UGS PCB. If someone has spare, let me know!

Thanks;

[Eric]

Wow, Martin! That is an EXCELLENT build!

I would certainly be interested in a remote volume board if they are available in some manner! I've been looking for a good remote unit for use in an upcoming DCB1 build...

[Tiroler]

Thanks Eric! I know that there is a lot of interest amongst UGS builders for a bespoke remote. Cheff DeGaar is the man that could develop that..! Guess we have to wait.
Martin

[dsdjoy]

Originally Posted by Manu

Hope you solved your problem ..

Manu

Tried, tried, but no success yet.

I rebuild completely the Logic/Relais section in power supply.
The Mikroprozessor board is working again...yeah....but the relais boards are not working.

First I checked the Mikroprozessor. This one was ok, it switched it outputs between 0V and 5 Volt.

Then I checked the power supply for the Relais boards. Voltage breaks down from 24 Volt to 2.3 volt.

I inserted a 10 Ohm resistor into the 24V supply line for the Relais boards.
measuring 10Volt across the 10 Ohm resistor !
My math says that the relais boards are consuming too much current (1 Amp)- and voltage from 7824 regulator breaks down. (I have only 1 channel out of two relais boards connected).

I measured coil resistance of all relais . All are around 2.7 to 2.9 kOhm. So no short circuit here....

There are 3 Darlington Array Chips on the Relais board, which switch the relais. I was thinking that maybe those chips have a short circuit. I unsoldered all 3 Darlington Array chips (ULN2003, ULN2803) from one relais board.

I then inserted a brand new ULN2003 DIP16 into the socket of 1 board. This Dip16 socket chip is responsible only for switching 3 relais. I did NOT solder the other two Darlington Array chips to the board which would handle volume and input switching. I then connected the single (one out of two channels) board to Mikroprozessor board and supply.

Same effect:
The single, new ULN2003 chip consumes 1 Amp current (max. that the 7824 delivers) and gets very hot.....was there some smoke... ?

I am lost....what is wrong here ?

Schematic: http://psykok.homelinux.org/diy/prea...urs/Atours.pdf

PDF page 2:
I did connect only one side.
In the end for testing purposes only IC2 soldered (not IC1, IC3).

[meldano]

Hi,

it look like a short circuit.
What is with the capacitors at the relay coils?



Dan