Rectifiers
AssigneeEddystone Radio Limited
InventorRoger T. Sutton
Life of this patent
Estimating the term…
Abstract
A rectifier is arranged to enable predetermined profiles for charging and discharging a capacitor to be satisfied over a wide dynamic range of input signals. The feedback loop is provided in which a charging resistance, a charging capacitor, a discharge resistor and a rectifying element are provided as separate items.
Claims9
A rectifier including a capacitor, a rectifying device constituted by a transistor which is arranged to charge said capacitor in response to an input signal applied to the rectifier;
- means for sensing the magnitude of the voltage on the capacitor and for driving a current through the transistor which is directly proportional to the difference between the magnitude of the input signal and the instantaneous value on the capacitor;
- said means including a comparator circuit having two input terminals, a resistance connected to one input terminal and being arranged to receive the input signal, the other input terminal being arranged to receive a signal representative of the instantaneous voltage on the capacitor, the base of said transistor being driven by the output of the comparator circuit and the emitter-collector path of said transistor being connected between said one input terminal and said capacitor whereby the charging time constant of said capacitor is dependent on the value of said resistance.
A rectifier circuit having a precisely definable charge time constant which is properly exponential in profile over a very wide dynamic range of input signal levels, which comprises in combination:
- a comparator having a pair of input terminals and an output terminal,
- a resistor connected to one of said input terminals and providing an input path for the input signal to said one input terminal,
- rectifier means also connected to said one input terminal and to said output terminal for controlling current flow through said resistor, during like polarity half cycles of the input signal, in accord with the output at said output terminal,
- a capacitor and means for charging said capacitor with a current directly proportional to the current controlled by said rectifier means;
- and
- means controlling the voltage value of the other input terminal of the comparator in accord with the instantaneous voltage on said capacitor whereby the charge time constant of said capacitor is precisely defined by said resistor and is exponential in profile over a very wide dynamic range of input signal levels.
Dependencies are inferred from the claim text.