GB2480239A - Automatic parallel to serial circuit reconfiguration - Google Patents

Abstract

Circuit elements such as relay coils 6,7, or resistors, automatically change from an initial parallel configuration to a series configuration. Current can be controlled by capacitors 8,9 which define the parallel time by conducting until the sum of their voltages is equal to the applied DC voltage whereupon diode 5 is forward biased and the circuit elements are subsequently in series. Relay coils 6,7 may be on the same magnetic core and normally closed contacts (fig 3, 10,11) can be used to control the current. A snubber diode (fig 3, 12) can be used to suppress transient surges. The excess power required to initially actuate the device is reduced to the power required to maintain the energised state.

Description

Electrical circuit reconfigurator This invention relates to d.c. control circuits for electrical and electromagnetic devices.

Many electrical and electromagnetic devices require more initial power than is necessary to maintain the device in the actuated state.

To reduce the excess power used in the actuated state the present invention can reconfigure a device where the electrical powered circuit can be realised as two separate elements. The elements may be electromagnetic coils or resistances. The circuit reconfigures an initial parallel connection of the two elements to a series connection. This change in configuration reduces the power required to maintain the energised state.

In the case of electromagnetic relays or solenoids the usual copper coil would be changed to two coils. The two coil device would typically, but not necessarily, contain the same amount of copper as in a similar standard device.

The reconfigurator circuits are inherently self timing and, in the case of electromagnetic devices, include the snubber or transient suppression function.

Relays using the reconfigurator circuits will, typically, be operable from low power logic circuits.

The invention will be described with reference to the accompanying drawings. Figure 1 shows the circuit with two elements to be reconfigured, 1 and 2. Elements 3 and 4 are current control components. Element 5 shows a diode.

Figure 2 shows a circuit where the controlled elements 6 and 7 are electromagnetic relay coils, with the currents controlled by capacitors 8 and 9.

Figure 3 shows a circuit where the electromagnetic relay coils 6 and 7 are controlled by normally closed contacts 10 and 11 on the relay.

With reference to Figure 1. The function of the circuit is to automatically change the configuration of the two circuit elements I and 2 from a parallel connection at the time when the control voltage Vc+ is first applied; to a series connection after a defined time delay.

The configuration is determined by the circuit elements 3 and 4. Elements 3 and 4 can be realised with a number of different electrical and electronic components.

The reconfiguration sequence starts when a positive d.c. control voltage is applied to the Vc+ line, referenced to the Vo line. Elements 3 and 4 are in a conducting state and the diode 5 is reversed biased and not conducting. Elements 3 and 4 are conducting in a parallel configuration. After a pre-defined time, elements 3 and 4, the control elements, operate to reduce the current flowing through them causing the voltage across elements I and 2 to reduce and diode 5 to conduct together with elements I and 2 in a series configuration.

The circuit of Figure 2 would typically, but not necessarily, be used with electromagnetic relays or similar devices. Circuit elements I and 2 are two coils on the same relay magnetic core, and elements 8 and 9 are capacitors. The capacitors provide the reconfiguration function. Timing is defined by the capacitors and the characteristics of the two relay coils. The capacitors start to charge when a positive voltage is applied to the control input Vc+, and continue to charge, with elements I and 2 in parallel, until the sum of the two capacitor voltages are equal to the voltage Vc+ at which point the diode 5 becomes forward biased, and together with coils I and 2 conducts in a series configuration.

Surge suppression or snubber circuits are invariably required when electromagnets or other inductors are operated by mechanical switches or semiconductor devices.

The reconfigurator circuit includes the transient suppressor function, which is inherent in the circuit.

The circuit of Figure 3 is shown with elements 10 and 11 as contacts on the relay to be energised. The normally closed contacts 10 and 11 are set to open before the relay armature has completed its travel to the final energised position. Elements 6 and 7 are the two relay coils and element 12 provides transient protection.

Claims (3)

1. Claims 1 A reconfiguration circuit which changes the connection of two circuit elements from an initial parallel configuration to a series configuration.
2. 2 A reconfiguration circuit according to claim 1, in which the circuit elements are relay coils in which the current is controlled by capacitors, shown in Figure 2.
3. 3 A reconfigurator circuit according to claim 2 in which the relay coil current is controlled by normally closed relay contacts 10 and 11, with the snubber function provided by the diode 12, as shown in Figure 3.Amendments to the claims have been filed as follows: Claim 1 A dual coil electromagnetic circuit in which the coil connections are changed, following the application of a d.c. voltage, from a parallel to a series configuration by the charging of two capacitors. * S S.... * SS .5. * S. * S S 55. *S SS S I **