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Constant Voltage Generator

IP.com Disclosure Number: IPCOM000089563D
Original Publication Date: 1977-Nov-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 3 page(s) / 35K

Publishing Venue

IBM

Related People

Madyiwa, SP: AUTHOR

Abstract

A constant voltage source or current source generator consists of three parallel electrical paths between V(CC) and V(EE). The first electrical path includes a series connection of a first NPN transistor T1, a second NPN transistor T2 and two resistors R1 and R2. The second path consists of first and second NPN transistors T3 and T4 and a series-connected resistor R3 connected to the emitter of the second transistor T4. The third electrical path consists of an NPN transistor T5 and a series-connected resistor R4. The output voltage VA is obtained at the connection between the resistor R4 and the emitter of the NPN transistor T5 in the third electrical path.

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Constant Voltage Generator

A constant voltage source or current source generator consists of three parallel electrical paths between V(CC) and V(EE). The first electrical path includes a series connection of a first NPN transistor T1, a second NPN transistor T2 and two resistors R1 and R2. The second path consists of first and second NPN transistors T3 and T4 and a series-connected resistor R3 connected to the emitter of the second transistor T4. The third electrical path consists of an NPN transistor T5 and a series-connected resistor R4. The output voltage VA is obtained at the connection between the resistor R4 and the emitter of the NPN transistor T5 in the third electrical path.

The base of the NPN transistor T1 in the first electrical path is connected to ground potential tending to bias this transistor into conduction depending on the potential drop across the resistors R1 and R2 (which is determined by the current flow). The output node N1 at the collector of this transistor is connected to the base of the transistor T3 in the second electrical path. The bias on the base of the transistor T3 determines the potential level at its emitter node N2, which in turn is connected to the base of the transistor T5 in the third electrical path, effecting its level of conductivity and the output voltage VA. The output voltage is connected to the base of transistor T4 in the second electrical path, effecting the potential at its collector. The output voltage is also connected to the base of the transistor T2 in the first electrical path, effecting its conductivity and the current flow in the first electrical path. The current flow effects the potential drop across the resistor R1 in the first electrical circuit, thereby effecting the potential at node N1 which adjusts the voltage output at VA.

Assuming th...