Charles,
Attached is another way to do it. A higher charging voltage
increases capacitor voltage linearity over the range of the ADC
making curve compensation easier.
The bus switch has a very low on resistance to pretty much discharge
the cap. The design is pretty old - I'm sure there are
Use the phase detector output to drive the tristate control input of a fast
CMOS tristate state buffer (eg 74HC126 or faster) which in turn drives the RC
network eliminating the diode.
Then correct for the exponential charging characteristics using the micro.
For best results increase ADC
Charles wrote,
>
> According to my tests, the B-C junction of a high-quality 2N3904 has
> about 50pA of leakage at 20vDC reverse voltage.
That's good to know, but the problem I had with this circuit was with the
forward current at a low forward voltage. With this phase detector, the
HC4046 makes
Hi Jim,
On 09/08/2018 10:02 PM, Jim Harman wrote:
> Magnus said,
>
> It would be interesting to test the linearity of the TIC separately for
>
> instance.
>
> I have done some testing of the TIC. It works quite well for the Arduino
> Uno with its 1 V full scale ADC setting, but the exponential
Magnus said,
It would be interesting to test the linearity of the TIC separately for
instance.
I have done some testing of the TIC. It works quite well for the Arduino
Uno with its 1 V full scale ADC setting, but the exponential shape of the
RC charging from the 5 V is quite evident if you use
Lady Heather now has some partial support for the Lars GPSDO. It does not
directly send any commands to the device (I don't have one yet to implement
that), but you can use the !u or !t keyboard commands to do that,
Heather treats the Lars GPSDO as a time interval counter. You need to start
