Light meter
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
Aug 19, 1980
Grant Date -
N/A
app pub date -
Aug 21, 1978
filing date -
Aug 21, 1978
priority date (Note) -
Expired
status (Latency Note)
Importance
Abstract
To permit a portable light meter to operate without zero adjustment and without excessive battery drain, a chopper-stabilized amplifier amplifies the DC signal from the light sensor of the light meter. The chopper in the chopper-stabilized amplifier is an FET circuit having a high impedance compensating circuit to avoid battery drain while compensating for interelectrode capacitance. The power supply obtains the ground level potential from the output of an operational amplifier with negative and positive potentials being generated from that reference potential so as to not require a center tap on the battery pack.
First Claim
Family
International Classification(s)
- [Classification Symbol]
- [Patents Count]
Cited Art Landscape
Patent Citation Ranking
Recipient Email Address
Recipient Email Address
Comment
Recipient Email Address
Add to Portfolio(s)
To add this patent to one, or more, of your portfolios, simply click the add button.
This Patent is in these Portfolios:
Add to additional portfolios:
Last Refreshed On:
Changes done successfully