[volt-nuts] Voltage to frequency

[John Devereux]

The main issue here is that any "frequency to voltage" or "voltage to
frequency" will still need a precision voltage reference *as well* as,
now, a precision frequency reference. So you are no further forward. You
may as well just use the voltage reference directly!

As Mitch says there are also precision PWM circuits, but these too need
a voltage reference in the circuit. The advantage with PWM is that it is
possible to generate very accurate ratios (or make adjustments) without
needing precision resistors.

PWM is probably the way to go for a precision *variable* voltage. But it
does not get you out of needing a precision fixed voltage reference to
refer it to.

John


"Mitch Van Ochten" <mitch at vincentelectronics.com> writes:

> Virtually all of the adjustable calibrators from Fluke, Valhalla, and
> others do a PWM to precision voltage conversion.
>
>
> Regards,
>
> Mitch
> ----- Original Message ----- 
> From: "Steve - Home" <steve-krull at cox.net>
> To: "Discussion of precise voltage measurement" <volt-nuts at febo.com>
> Sent: Monday, July 29, 2013 4:09 PM
> Subject: Re: [volt-nuts] Voltage to frequency
>
>
>> Joe,
>>
>> Loss of accuracy in the conversion process is probably the biggest
>> reason. It's also less complex to build the voltage standard to a
>> higher degree of accuracy and stability than to build an accurate,
>> stable frequency standard AND an accurate, stable V to F converter.
>>
>> Steve
>> WB0DBS
>>
>>
>>
>> On Jul 29, 2013, at 2:55 PM, Joseph Gray <jgray at zianet.com> wrote:
>>
>>> I imagine that this has been discussed before, but I didn't see
>>> anything in
>>> the archives. Long before my recent weakness and ordering of that voltage
>>> standard on ebay, I had thought about using a voltage to frequency
>>> converter.
>>>
>>> Since it is relatively easy and inexpensive to have a very accurate
>>> frequency standard at home, I wondered how difficult would it be to use
>>> that standard to create an accurate voltage standard.
>>>
>>> Some Googling didn't turn up much along these lines. Since this method
>>> apparently isn't being used, there must be some reason. Can anyone
>>> enlighten me?
>>>
>>> Joe Gray
>>> W5JG

-- 

John Devereux