silicon chip/jaycar kit

Posted: 3/16/2009 5:36:28 PM
maxiboy

Joined: 3/16/2009

Hi!
I am new here, an i found an old thread about this but didn't find any answers, and no one had been writing there for a long time, so i found it best to start a new topic.

I am building the silicon chip/jacar theremin kit, and i have encountered some problems. First: my IC2 doesn't have a cut so i put so you could read the text from the same way as the other two. Is this correct?

Second problem:
I don't get any voltage from the case of T1-T4 to the IC pins. Everything looks okay so does anyone know what the problem could be?

Thanks

ps. sry for bad english, i am from sweden. ds
Posted: 3/16/2009 6:22:57 PM
Thierry

From: Colmar, France

Joined: 12/31/2007

Please tell us which of the Jacar/Silicon Chip versions (there are 3 different releases) you are building, so that we may better help you!
Posted: 3/16/2009 6:29:21 PM
maxiboy

Joined: 3/16/2009

oh.... i got from thereminkits.com a few days ago? does it say something to you? cause i don't really know myself...
Posted: 3/16/2009 6:41:26 PM
djpb_designs

From: Escondido, CA

Joined: 2/6/2008

I am assuming that by "cut" you mean there is no silkscreen on the board to show you which way it is to be installed?

There was someone just a few days back who found they had one of the ICs in backwards in their Jaycar kit. The symptom they had was that the regular was getting very hot. Which could indicate a number of potential problems.

Don
Posted: 3/16/2009 6:44:15 PM
maxiboy

Joined: 3/16/2009

thanks, well there isn't anything that gets very hot so, than it might be in the right direction :)

but the other problem is probably more important to solve... any ideas?
Posted: 3/16/2009 6:55:41 PM
Thierry

From: Colmar, France

Joined: 12/31/2007

That is the MK I version. :-)

IC2 should be placed that the "LM 358" writing is read in the same direction as the "LM 386" writing on IC3.

Concerning the presence of voltages:

Verify the presence of the power supply voltage at both pins of the power switch and keep this value in mind. The same value minus ca. 0.6V should appear at the input of REG1. At the gound pin of REG1 you should find 0.6V and at the output pin ca. 5.7V
Tell us if all these voltages are already present?

sry for my bad English - I'm from France...
Posted: 3/16/2009 7:00:49 PM
maxiboy

Joined: 3/16/2009

I won't be able to do this today but i will report as fast as i have done it! thanks for your helpfullness! :D
Posted: 3/18/2009 10:30:33 AM
maxiboy

Joined: 3/16/2009

I don't really get what positions i am goind to try between... i just get about 9 v!
Posted: 3/18/2009 12:31:20 PM
Thierry

From: Colmar, France

Joined: 12/31/2007

But you understand the schematic and the function of your theremin, don't you?

I uploaded a copy of the schematics where I wrote the Voltages that you should find in the first step:

Click here (http://www.tfrenkel.com/theremin/sc-diagram.png)
Posted: 3/18/2009 5:54:51 PM
maxiboy

Joined: 3/16/2009

yeah that helps a lot thanks!

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