60 Hz Frequency Reference

If frequency [Fr] is not critical : 555 is ok. else use xtal.

If waveform is critical (<1% error) Higher fr. osc, divider-
sine PROM - DAC ELSE function generator chip. If even less
critical (>5% error ) :lp filter.




<nbucska@pcperipherals.com>

For voltage you can use an H driver for up to 24V.
-- you neglected to mention how much current do you need
to supply.

If difficulty, send fax# for schematics anf full specs.

<nbucska@pcperipherals.com>

Rawlings,

Try ML2036 or ML2035 from fairchild, this a simple DDS frequency generator with senoidal output. You need add a low pass filter and operational amplifier to obtain a desired output level. This device operate in any frequency from DC to 25KHz.



Regards,

M3

If you live in an area where line power is 60 Hz, then why not just use a transformer and a potentiometer to control the amplitued? If you require a buffered signal, then a DC supply will also be needed. I believe that line frequency is very stable.

I agree with garry.

Unless you have some good reason to avoid the transformer, I'd just dig up one of the old wall wart transformers (from some long-forgotton home electronics) that you most likely have laying around in a junk drawer somewhere in your kitchen or basement. Just plug it in and voila, you have a free, very accurate and very stable 60Hz reference source.

Matter of fact, it's a good enough reference that not only old clocks, but some old TV's used to use the power supply for their time base.

There are a lot of good stable Wien bridge oscillator circuits out there that will probably do the trick for you and also have very low distortion figures. You could use a function generator chip, but you must keep in mind they are terribly sensitive to temperature changes, even if the component values used are temperature stable.

Depending upon frequency accuracy required, one choice might be a Fairchild ML2036 chip. Data sheet at:
app note at:Available from Arrow electronics for $8.81. It runs on 5 volts, so you'll have to amplify it up and produce current u need. Also u have to load divider number in and provide either an external clock, or a ref crystal. It gives you about 1 Hz steps in produced frequency. Suitable xtals are listed on data sheet, or i'm gonna try a color telly xtal, cause i have those on hand. Implemented, this shouldn't cost more than $25 or so for low power levels.

I need it for a 50 Hz ref for a VCR (you can play PAL tapes on a usa vcr (NTSC) if you provide a 50 Hz ref to the head wheel circuitry. video comes out at a 50 Hz frame rate tho, so you need a tv with a vertical hold control to display picture.

Have fun..

Rab

Hi Bunny01:

I don't believe the VCR speed control would need sine
I think XTAL--digital divider and perhaps amplifier
should do it.


<nbucska@pcperipherals.com>