Circuitbenders Forum

Please login or register.

Login with username, password and session length
Advanced search  

News:

Author Topic: Installing a LTC1799 clock oscillator - a basic guide  (Read 5495 times)

Circuitbenders

  • crustypaul
  • Admin
  • This person is dangerously insane.
  • *****
  • Karma: 1102
  • Offline Offline
  • Posts: 2440
    • Circuitbenders.co.uk
Installing a LTC1799 clock oscillator - a basic guide
« on: January 20, 2011, 06:52:10 PM »

I've just put together a basic general guide on actually installing an LTC1799 based oscillator, over on the main site. It covers the basics of finding and removing the existing clock source, installing the LTC1799 and using switching to select the original or replacement clock.

http://www.circuitbenders.co.uk/tutorials/LTCinstallation1.html

Any suggestions are welcome, but bear in mind this is meant to be as basic as possible and doesn't cover any specific machines.
Logged
i am not paid to listen to this drivel, you are a terminal fool

wax+wire

  • Way to much time on his hands
  • **
  • Karma: 0
  • Offline Offline
  • Posts: 99
Re: Installing a LTC1799 clock oscillator - a basic guide
« Reply #1 on: August 26, 2015, 08:32:39 AM »

reading the LTC 1799 it talks about a Voltage Controlled mode::

Figure 4 shows the LTC1799 configured as a VCO. A voltage source is connected in series with an external 10k resistor.
The output frequency, fOSC, will vary with VCONTROL, that is the voltage source connected between V+ and the SET pin. Again, this circuit decouples the relationship between the input current and the voltage between V+
and SET; the frequency accuracy will be degraded. The oscillator frequency, however, will monotonically increase
with decreasing VCONTROL

https://cds.linear.com/docs/en/datasheet/1799fc.pdf

That seems like an interesting potential function for a vibrato add in for the LTC1799 clock

What confuses me is that it draws in the circuit diagram (Figure 4 in the .pdf) the clock source as a + - device, like an LED or capacitor, but i'm only used to thinking of CV like a input pin on a 555 oscillator.

Could i make a 555 oscillate between 0-1.13V to create an LFO vibrato?? hmm.
Logged

wax+wire

  • Way to much time on his hands
  • **
  • Karma: 0
  • Offline Offline
  • Posts: 99
Logged

Circuitbenders

  • crustypaul
  • Admin
  • This person is dangerously insane.
  • *****
  • Karma: 1102
  • Offline Offline
  • Posts: 2440
    • Circuitbenders.co.uk
Re: Installing a LTC1799 clock oscillator - a basic guide
« Reply #3 on: August 26, 2015, 09:07:54 PM »

interesting, although 0-1.13v is a little on the restrictive side to say the least!

If its that sensitive it might be worthwhile sticking in a zener diode in give some kind of over voltage protection.
Logged
i am not paid to listen to this drivel, you are a terminal fool

wax+wire

  • Way to much time on his hands
  • **
  • Karma: 0
  • Offline Offline
  • Posts: 99
Re: Installing a LTC1799 clock oscillator - a basic guide
« Reply #4 on: September 06, 2015, 10:12:34 PM »

Haven't given this ago yet but there are few websites i've found (though none in english!) that seem to have some circuits

http://www.peter-boesche.de/ltc1799.htm
Logged

wax+wire

  • Way to much time on his hands
  • **
  • Karma: 0
  • Offline Offline
  • Posts: 99
Re: Installing a LTC1799 clock oscillator - a basic guide
« Reply #5 on: September 13, 2015, 04:32:16 AM »

So I used this circuit:
http://www.555-timer-circuits.com/up-down-fading-led.html
And swapped out the 33K resistor for a 10K potentiometer to have a rate control, and a switch in series (the switch turns the vibrato on and off) and I tapped the voltage at the LED and stuck a 1M pot between the 555's oscillating voltage and the LTC 1799's pin 3.

The result is clean vibrato with good rate control, but not proper depth control.  Instead of altering the *with* of the pitch oscillation, as I'd want, the 1M pot alters the base frequency significantly, and the width a little.

I wonder whether i would be able to get vibrato depth out of a circuit like this.
Logged