GB1342737A - - Google Patents
Info
- Publication number
- GB1342737A GB1342737A GB1342737DA GB1342737A GB 1342737 A GB1342737 A GB 1342737A GB 1342737D A GB1342737D A GB 1342737DA GB 1342737 A GB1342737 A GB 1342737A
- Authority
- GB
- United Kingdom
- Prior art keywords
- transistor
- coil
- relay
- transistors
- circuit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
- H03F1/52—Circuit arrangements for protecting such amplifiers
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/20—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for electronic equipment
- H02H7/205—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for electronic equipment for controlled semi-conductors which are not included in a specific circuit arrangement
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
- H03K17/08—Modifications for protecting switching circuit against overcurrent or overvoltage
- H03K17/081—Modifications for protecting switching circuit against overcurrent or overvoltage without feedback from the output circuit to the control circuit
- H03K17/0814—Modifications for protecting switching circuit against overcurrent or overvoltage without feedback from the output circuit to the control circuit by measures taken in the output circuit
- H03K17/08146—Modifications for protecting switching circuit against overcurrent or overvoltage without feedback from the output circuit to the control circuit by measures taken in the output circuit in bipolar transistor switches
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
- H03K17/08—Modifications for protecting switching circuit against overcurrent or overvoltage
- H03K17/082—Modifications for protecting switching circuit against overcurrent or overvoltage by feedback from the output to the control circuit
- H03K17/0826—Modifications for protecting switching circuit against overcurrent or overvoltage by feedback from the output to the control circuit in bipolar transistor switches
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Relay Circuits (AREA)
- Emergency Protection Circuit Devices (AREA)
Abstract
1342737 Protective arrangements DERRITRON ELECTRONICS Ltd 20 July 1971 [23 April 1970] 19569/70 Heading H2K [Also in Division H3] A protective system in a transistor power amplifier includes a reed relay 35 having two coils 36, 37, the coil 36 being fed with a signal corresponding to the voltage across an output transistor 21 and the coil 37 being fed with a signal corresponding to the current through the same transistor. As shown, the coil 36 is connected in series with a resistor 33 and a Zener diode 32 across supply conductors 25, 26, and the coil 37 is connected across a resistor 28, which is in series with the transistor. An isolating diode 29 enables the relay to be connected to a plurality of transistors in a module for response when any of the transistors is overloaded. A plurality of such modules may have a like plurality of reed relays with their contacts connected to common conductors 38, 39 extending to a trigger circuit comprising a long tailed pair of transistors controlling a further relay, Figs. 3A, 3B (not shown). The system may cut off the power supply to the amplifier, to its out put stage or to a transistor. It may drain off power stored in the supply circuit, e.g. in capacitors, using a thyristor, Fig. 4 (not shown). The further relay may have contacts connected in circuit between an oscillator and a phase splitter, Figs. 3A, 3B (not shown). Reed relays having single coils connected for response to overvoltage condition may also be provided.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1956970 | 1970-04-23 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1342737A true GB1342737A (en) | 1974-01-03 |
Family
ID=10131570
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB1342737D Expired GB1342737A (en) | 1970-04-23 | 1970-04-23 |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB1342737A (en) |
-
1970
- 1970-04-23 GB GB1342737D patent/GB1342737A/en not_active Expired
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PS | Patent sealed | ||
| PCNP | Patent ceased through non-payment of renewal fee |