Back to results
US 4,733,193 AGranted
Arrangement for eliminating signal hum
OwnerJiri Klokockainventor
Life of this patent
Estimating the term…
Abstract
A circuit for eliminating signal hum includes, in series, an adder 17, a delay circuit 13, an amplifier 19 and a subtractor 14. Connected in parallel with the delay circuit is a feedback loop having an amplifier 18 connected to one input 172 of the adder. The circuit input 11 is connected to the input of the series coupling, and to an input 142 on the subtractor. The delay circuit has a control input connected to a second signal input, via a synchronizing circuit 16.
Claims13
An arrangement for eliminating signal hum, comprising a first signal input (11) for supplying the signal to the arrangement;
- a second signal input (12) for supplying to the arrangement a hum signal of the same frequency as one of the partial frequencies of the hum;
- a delay circuit (13) having an input (131) connected to the first signal input (11), and an output (132) connected to a substraction circuit (14), which has a second input (142) connected to the first signal input (11), and has an output (143) connected to the output (144) of the arrangement;
- and
- a synchronizing circuit (16) between the second signal input (12) and a control input (133) on the delay circuit (13), characterized in that an addition circuit (17) is connected between the first signal input (11) and the input (131) of the delay circuit (13);
- in that a first amplifier (18) having an. amplification factor a according to the relationship:
- O.ltoreq.a.ltoreq.1 is coupled between the output (132) of the delay circuit and the second input (172) of the addition circuit (17);
- and in that a second amplifier (19) having an amplification factor b according to the relationship 0.ltoreq.b.ltoreq.1 is coupled between the output (132) of the delay circuit (13) and the first input (141) of the subtraction circuit (14).
4 more elements
Dependencies are inferred from the claim text.