The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 17, 2018
Filed:
Dec. 16, 2013
Sondex Wireline Limited, Yately, Hampshire, GB;
Kenneth Tomkins, Hampshire, GB;
Sondex Wireline Limited, Farnborough, Hampshire, GB;
Abstract
A peak hold circuit configured for use in a downhole sensor includes a long tail pair circuit, a correction circuit, and a current mirror circuit. The current mirror circuit includes two current mirrors connected to a long tail pair formed by a first transistor and a second transistor. The current mirror also includes a first resistor and a second resistor connected to a third transistor. The first transistor is connected to a correction transistor of the correction circuit. The value of the first resistor is selected to be essentially equal to the same value as the second resistor so that when the long tail pair is balanced, the current flowing through a collector of the second transistor is equal to the current flowing through the first transistor, causing the correction transistor to switch off.