The Shop > Electronics & IC Programing
Digital oscilloscope project/kit
RobWilson:
Hi John , I can't find a circuit diagram for this project , I was just hoping that there was a 9v Reg in the same package I could just solder in place .
But I am always up for madmodding lol
Rob
John Rudd:
Rob,
What about a link to the kit you bought?
The little 3.3v regulator wont have enough juice applied to it to get 9v out...that is, the 3v reg will only have about 6v in to it to reduce its dissipation....so a drop in wont work
You may have to cobble something using the 12 v side.....
John Swift:
Hi Rob
in the advert they say they don't provide a schematic !!! - no good for modders :lol:
I guess the switching power supply generates some thing like plus and minus 18V
the positive SMP output supplies the 78M12 and 78M05 regulators for the +12V and +5V outputs
and the negative SMP supplies the 79M12 and 79M05 regulators for the -12V and - 5V outputs
the "1117" 3.3V regulator looks like is powered by the +5V regulator (78M05)
to add a 9V regulator you need to either tap into the supply to the 12V regulator or the 12V output
the 9V regulator can be a 78M09 or a LM317 adjustable regulator and resistors
John
PS
Do you had a photo showing the PCB tracks of the other side of the board
wheeltapper:
Hi Rob.
I'm still waiting for my power supply kit to arrive, it was allegedly posted on the 30 Jan so where is it :bang: :bang: :bang: :bang:
I've got the sig gen kit but I want to get the supply running before I build it or it will sit there and annoy me.
I built the frequency counter kit and that works OK ( even tho I said I wasn't going to get it ) :doh:
I'm also thinking of getting this http://www.banggood.com/DIY-Aviation-Band-Receiver-Kit-High-Sensitivity-p-990306.html as I live near Norwich airport.
could someone look at the schematic of this receiver and tell me if I could connect the frequency counter to it to check the receiving frequency.
cheers
Roy.
John Swift:
Hi Wheeltapper
you need a frequency counter that the displayed frequency can be off set by 10.7MHz
this avoids having do the maths to work out what its tuned to
looking at the circuit the coil L6 , capacitor C14 and varicap diode D1 set the frequency of the local oscillator (part of U1) - this is what needs to be the input to the counter
the output of the oscillator is mixed with the signal you want to receive
the difference between the two has to be 10.7MHz to pass through 10MHz filter fil1
and when amplified by Q1 and U2 pass through the IF transformer T1
D1 is the AM detector that resolves the audio signal to be amplified to drive the loud speaker or headphones
john
PS
a frequency display like this -
http://www.ebay.co.uk/itm/50MHz-LCD-Frequency-Counter-Module-with-IF-Offset-Free-UK-Postage-/172103761140?hash=item28122efcf4:g:mKAAAOxyThVTXnoD
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