[time-nuts] Parallel voltage regulators

[Bruce Griffiths]

Don Collie wrote:
> I`ve always wondered about noise from batteries - please tell us more 
> Bruce!! [....also wondered about noise from the electrolytic action of 
> aluminium, and tantalum electrolytic capacitors, and wondered if the 
> reference bypass capacitor in a 723 should be a plastic dielectric type, 
> rather than electrolytic].........
> .......................................................Don C.
>
>   
Don

A plastic dielectric capacitor for the reference bypass is best (X7R
ceramic may also be usable) as the leakage is lower as is the noise.
Yes electrolytics are noisy especially at low frequencies.
Aluminium electros can be noisier than tantalum electros.
NIST prefer plastic bypass caps paralleled by ceramic caps to bypass the
base of their RF isolation amplifiers.

Battery noise links:
http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=ELLEAK000001000005000132000001&idtype=cvips&gifs=yes
<http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=ELLEAK000001000005000132000001&idtype=cvips&gifs=yes>
Note the high excess noise of the carbon resistors favoured by some
audio nuts.

http://ieeexplore.ieee.org/Xplore/login.jsp?url=/iel2/3499/10330/00483923.pdf?arnumber=483923

There is also a more accessible article somewhere, I'll try to find it.

Bruce