Gig-Ohm resistor

I have never heard the term Gigaohms used with resistors. Is this a
valid term? With computer hard drives, if a drive is 1000 megabytes,
it's called one gigabyte.

Using some resistor color code software I have, it does not use that
term. For example, brown black gray says 1000M. or red red white is
listed as 22,000M

In real life I have never used any resistor with that high of a
capacity, I dont even know if they are made, but would 1G or 22G be
valid for the examples above?

 

[N_Cook]

On 01/02/2019 18:56, tubeguy@myshop.com wrote:

I have never heard the term Gigaohms used with resistors. Is this a
valid term? With computer hard drives, if a drive is 1000 megabytes,
it's called one gigabyte.

Using some resistor color code software I have, it does not use that
term. For example, brown black gray says 1000M. or red red white is
listed as 22,000M

In real life I have never used any resistor with that high of a
capacity, I dont even know if they are made, but would 1G or 22G be
valid for the examples above?

I have a number of high precision multi-Gohm resistors, for calibrating
RLC meters, for when I used to repair those. They look like reed relays
at first sight, enclosed in presumably evacuated glass envelopes.

 

[Phil Allison]

tub...@myshop.com wrote:

I have never heard the term Gigaohms used with resistors. Is this a
valid term? With computer hard drives, if a drive is 1000 megabytes,
it's called one gigabyte.

Using some resistor color code software I have, it does not use that
term. For example, brown black gray says 1000M. or red red white is
listed as 22,000M

In real life I have never used any resistor with that high of a
capacity, I dont even know if they are made, but would 1G or 22G be
valid for the examples above?

** Tube and FET condenser microphones use resistors of 1 or 2 Gohms.

Example:

https://www.ebay.com/itm/Resistor-1G-1-Giga-ohms-1000-Mohms-new-0-25W-for-condenser-microphone-/361824019406


...... Phil

 

[Phil Hobbs]

On 2/1/19 1:56 PM, tubeguy@myshop.com wrote:

I have never heard the term Gigaohms used with resistors. Is this a
valid term? With computer hard drives, if a drive is 1000 megabytes,
it's called one gigabyte.

Using some resistor color code software I have, it does not use that
term. For example, brown black gray says 1000M. or red red white is
listed as 22,000M

In real life I have never used any resistor with that high of a
capacity, I dont even know if they are made, but would 1G or 22G be
valid for the examples above?


Sure, why not?

I've designed instrument front ends using resistors as large as 50G,
which you can get from Digikey. (In fact they sell 500 Gohm resistors
in surface mount.)

One thing to remember is that they're very very slow--a 500G resistor
makes a 1-second time constant with 2 pF!

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[legg]

On Fri, 01 Feb 2019 12:56:00 -0600, tubeguy@myshop.com wrote:

I have never heard the term Gigaohms used with resistors. Is this a
valid term? With computer hard drives, if a drive is 1000 megabytes,
it's called one gigabyte.

Using some resistor color code software I have, it does not use that
term. For example, brown black gray says 1000M. or red red white is
listed as 22,000M

In real life I have never used any resistor with that high of a
capacity, I dont even know if they are made, but would 1G or 22G be
valid for the examples above?

There may be a safety requirement to discharge across a safety
barrier, without affecting normal leakage, for static discharge.

RL

 

[Ron D.]

Yep have used G ohm resistors and have measured currents in the 1E-12 region.

For that matter I replaced a 10 megohm 200 Watt resistor. It was a bleed resistor on a 15 kV supply,