Richard R. Pope wrote 2014-07-25 17:14:
> Hello all,
>       I just posted some pictures...

Where?

Jan-Erik.



> showing my lab and the frequency
> counter that I am building. Keep in mind that this is just the
> prototyping stage. I complete a section, build a test setup, and then go
> on to the next section. The display board that is mounted to the larger
> board is completed. The larger board is just a test fixture that I will
> disassemble once I am finished with it.
>       My PicKitII is just in front of the display board. Behind the
> display board is one of my breadboards. It has the 74ls390s that are
> driving the CD4511s that are on the display board. You can also see the
> PIC16f684 on the right side of the breadboard. It is operating as a
> timebase and it controls the reset and gating functions. Eventually I
> will hook up a switch to control a variable timebase and the positioning
> of the decimal points. There will also be a pot to control the length of
> the display. Right now the display time is fixed at 5 seconds. On the
> left side of the breadboard is the signal conditioning circuitry and the
> NAND gate that is being driven by the gating signal coming from the PIC.
>       Behind the breadboard is my home made power supply. The meter on
> the far left is a 0-5 ammeter. The power switch, fuse, and the power
> light are next and in that order from bottom to top. The next meter is a
> 0-15 voltmeter. Next is the control for the variable voltage regulator.
> This is just the good old LM317. It is heat sinked to the back of the
> case. The fuse blown indicator is the red lamp that is above the pot for
> controlling the variable regulator.
>       The five green LEDs are +5, -5, +12, -12, and variable voltage
> indicators. These are hooked up right at the output pins of the
> regulators except for the adjustable regulator. It is hooked to the
> input pin. The rotary switch below the LEDs control which voltage and
> amperage are being displayed on the meters. This switch controls a
> series of small relays that switch the proper voltage regulator to the
> proper meters.
>       Behind that is my Tek 465B O-scope. To the left of the scope is my
> HP 5245L counter. The counter is showing the same 32.768KHz signal
> coming from a maxim DS32khz chip. This same signal is being displayed on
> my frequency counter and on the scope. My meter is reading +-1Hz of the
> HP counter. As you can see on the scope the signal has a very nice rise
> and fall time. The HP meter is connected to the back of the scope. This
> is the output of my front end circuitry for my counter. The front end
> will accept a signal as low as a few millivolts and to as high as 25
> volts. Sine, square, or irregular.
>       Everything is running on a regulated 5 volts and it is drawing a
> little over a 1/4 amp. There are pictures of the scope and HP counter
> and the home made counter and power supply. I would like to hear others
> comments. I hope that you enjoy. I'm happy. :)
>       Who posted the pictures of the racks of Tek equipment? I would like
> to know if that is possible.
> Thanks,
> rich!
>
--=20
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