SU620911A1 - Diode twin bridge - Google Patents

Description

(54) DOUBLE DIODE BRIDGE

one

This invention relates to electrical measurements. technology and can be used to create devices for measuring the parameters of electrical circuits.

Known resistive double T-shaped bridge containing resistors and capacitances 1). The disadvantages of this device are low sensitivity to changes in the parameters of the total monitored narrowness,

Closest to the proposed invention is a double diode bridge containing two parallel-connected T-shaped circuits, each of which is formed by a diode, a co-capacitor and a resistor, the diodes being connected in opposite polarity 2}. The disadvantages of this device are the low coefficient of conversion of the increment of the capacitance into an electrical signal and a narrow cavity.

The purpose of the invention is to increase the conversion ratio of the capacitance increment into an electrical signal and to expand the passband towards low frequencies,

To do this, in a known double diode, a bridge containing two parallel connected T-shaped circuits, each of which is formed by a diode, a capacitor, and. Reznstorom, and the doda included oppositely polarity, in each nz T-shaped circuits 5 introduced an additional bottom, included in the same polarity as the main, n additional capacitor, shunt the main and additional diodes.

In the drawing, daia is the electrical circuit of the proposed device.

It contains T-shaped circuits 1 and 2, which include respectively resistors RI and RS, capacitors Ci and Cj, diodes DI and DS, additional dades Da n D "and shunt capacitors Cj n € 4, 5 power sources E, load resistor R, and the filter capacitor in the load C.

The device works as follows.

In the negative half-period of the supply voltage, the capacitor Ci is charged

Claims (2)

The circuit voltage is E – D ,, –X – 1 – E to the voltage “–E, and the capacitor C |, charged in the previous half-period to“ 4-E, is discharged to the capacitor € 4 via the circuit Cg-. At the same time, Ci and Cd are charged from the generator along the 4-E-Q -Cj-i- -E circuit, and for Cd, these are charge of odium-polarity. In the positive half-period, the capacitor GI is charged along the circuit to the voltage ", + E, and the capacitor C is discharged by Cz along the circuit C, - OgS - - c simultaneously, C and Cj are charged from the generator along the circuit" +, and for Cj it is Charges are equally battlefield polarity. In both half-periods, Cz is discharged on C through Rt and Rj, but since the constant has been established: the discharge is several orders of magnitude longer than the constant charging time, residual charges of different polarity are preserved on Se and Cd; their magnitude depends on the ratio of capacitances (), the ratio of the constant time of the Cs (C4) charge circuits, and the frequency of the supply voltage. When Cj Cg is equal, the residual charges of Ca and C are equal in magnitude and opposite in sign — and the potential of point A is zero (average value). If capacitance C gains an increment in DC, i.e., GI Gj W-AC, then the residual charge of capacitor G will become greater than the charge of capacitance C4, and the potential of point A will no longer be equal to O — the load is constant at the load. Its value at fixed values of E and AG depends on the ratio of GI / GS (Gj / G), the ratio of the constant time and frequency of the supply voltage. When Sz C IOGi, G, - G ,; R.Ga RiG4 300 R.G ,. where Rd is the direct resistance of the diodes. The output voltage of the proposed bridge and, accordingly, the conversion factor is 2.0-3.0 times higher than in the scheme of the known bridge in equal conditions. Claims of the invention A double diode bridge comprising two parallel-connected T-shaped circuits, each of which is formed by a diode, a clamper and a resistor, and the diodes are connected in opposite directions, characterized in that in order to increase the capacitance conversion ratio of the electrical signal and bandwidth expansion in the direction of low frequencies, an additional diode is inserted in each of the T-shaped circuits, connected in the same polarity as the main one, and an additional capacitor, shunting the main and additional diodes s. Sources of information taken into account in the examination: 1. Golovyev A.N. Measuring equipment in a wired connection, ch. P, M., “Gz, 1969, p. 285-286. 2. Express information - “Testing and measuring equipment, 1975, No. 7, p. 7-16.