SU387305A1 - DEVICE FOR MEASURING THE STATIC TRANSFORMER COEFFICIENT OF THE TRANSISTOR CURRENT - Google Patents

Description

one

The invention relates to electronic engineering and can be applied to measure the parameters of transistors.

Devices are known for measuring the static current transfer ratio of transistors / ZaiE + l — In common-base circuits in which a constant voltage is applied to the collector from the source and the voltage drop across the base resistors is not taken into account. However, at high emitter currents and low voltages at the collector, this voltage drop cannot be neglected, since it introduces large errors in the measurement of the parameter / i2iE + l, especially in the boundary region of the measurement subranges.

The purpose of the invention is to improve the measurement accuracy / Zi2E + l. This is achieved by the fact that the detector output is additionally connected to an ohmic divider, the lower arm of which is connected in series with the reference source of the collector voltage stabilizer.

The drawing shows a block diagram of the proposed device.

The collector of the transistor under test / is connected to april stabilizer 2, consisting of a reference voltage source 5, a divider assembled on resistors 4 and 5, a comparison circuit and TFC 6, a regulating element 7 and a power source 8. Besides

In addition, the device contains a pulse emitter current regulator 9, a switch 10 sublimits, basic resistors // and 12, an amplifier 13 pulses, a detector 14 and an indicator 15.

When measuring / Z2iE + l transistors. The voltage drop across resistor 11 (or 12, depending on the subrange) is amplified by amplifier 13 and converted by detector 14 into

a constant voltage that is applied to a divider assembled on resistors 4 and 5. The divider division factor is equal to the conversion ratio of the amplifier and detector, and the voltage drop across resistor 4

will be equal to the voltage drop across the base resistor 11 or 12 and connected in series with the source 3 of the reference voltage. Thus, the reference voltage applied to the comparison circuit 6 increases by the magnitude of the voltage drop: resistor 11 or 12, and consequently, when the transfer coefficient of the DCF 6 and the regulating element 7 is equal to one, the constant voltage on the collector of the test the transistor will increase by the same amount.

Subject invention

A device for measuring the static current transfer ratio of transistors.

containing a pulsed emitter current regulator, a collector voltage regulator consisting of an ohmic divider and a voltage source, which through a DC amplifier is connected to a regulating element of a collector voltage source, a measurement limit switch, base resistors, amplifier, detector and indicator, characterized in that, in order to increase the measurement accuracy, the detector output is additionally connected to an ohmic divider, the lower arm of which is connected in series with the reference Source stabilizer collector voltage.