GB2189585A

GB2189585A - Delay switching system

Info

Publication number: GB2189585A
Application number: GB08609646A
Authority: GB
Inventors: Yong Kin Michael Ong
Original assignee: Individual
Current assignee: Individual
Priority date: 1986-04-21
Filing date: 1986-04-21
Publication date: 1987-10-28
Also published as: GB8609646D0

Abstract

A delay switching system 12 has three cable lead-out connection 1,2,3 meant to be connected to the magnetic clutch air-conditioner compressor unit 4. A delay switching system 12 provides a two to three seconds delay switch-on to the magnetic clutch air-conditioner compressor unit 4 after switching on the forced air cooling fan for the condenser unit 11. The delay switch-on of two to three seconds duration cycle is repeated each time the power supply line to cable 1 of the "Delay Switching System" is interrupted by operation of the thermostat functioning to its desired temperature setting. Existing cabling to the standard electrical connection of the motor car air-conditioner system is used for the functional power supply requirement of the delay switching system. <IMAGE>

Description

SPECIFICATION Delay switching system This invention relates to a delay switching system for motor car air-conditioner system.

Air-conditioner compressor units in motor cars are well known for its loading on the engines with major stress at the time that the compressor goes in service.

The standard electrical/electronic control devices in a car air-conditioner system comprises of a blower fan switch, thermostat, electrical controlled magnetic clutch compressor unit and a vacuum and/or auto relay switch (engine idle rpm air-conditioner cut-off control device).

Forced air cooling system for the car airconditioner system are normally driven by an electric fan and/or a direct mounted fan blade driven by the car engine to cool the condenser unit.

Forced air cooling system that operates on the electric fan is generally wired with the magnetic clutch compressor unit. This electrical connection configuration will cause a severe loading on the engine as well as the overall electrical system at the time the airconditioner system is triggered on.

The purpose of this invention is to improve the air-conditioner system through reducing the loading at the time the air-conditioner system is triggered on. This is achieved through a basic concept of sequential loading of the air-conditioner system by segregating the loading effects of the forced air cooling fan of the condenser unit and the magnetic clutch compressor unit. The sequential loading process is carried out by the "Delay Switching System" through its function of causing a switch-on delay effect of two to three seconds duration on the magnetic clutch compressor unit after the electric fan for the forced air cooling system of the condenser unit is switched on.

The operation of the "Delay-Switching System" is to provide a repeated cycle of thetwo to three seconds switch-on delay duration for the air-conditioner compressor unit after the forced air cooling fan is switched on each time the thermostat cut into service when the temperature is above the desired setting level.

A specific embodiment of the invention will now be described by way of the example with reference to the accompanying drawing in which: Figure 1 shows the standard electrical connection of the motor car air-conditioner system; Figure 2 shows the revised electrical connection of the motor car air-conditioner system using the "Delay Switching System"; Figure 3 shows the electronic circuitry of the "Delay Switching System"; Figure 4 shows the printed circuit board layout circuitry; and Figure 5 shows the component placement on the printed circuit board.

Referring to the drawing the "Delay Switching System" comprises of a 3 cable lead-out connection, viz the negative cable 3 for the car chassis, the positive cable 1 to be connected to the incoming positive supply line of the battery which in this case it is taken from the original termination to the magnetic clutch of the air-conditioner compressor unit and in replacement the magnetic clutch of the airconditioner compressor unit is connected to the delayed switch lead-out cable 2 (output).

The purpose of the 3 cable termination design of the "Delay Switching System" is to enable easy installation as well as to facilitate available electrical connection so as to eliminate unnecessary drawing of new cables to support the "Delay Switching System".

In order to provide isolation between the incoming positive supply line of the battery and the delayed switch lead-out (output), a relay 5 is used. The timing sequence is processed by a RC network, i.e. R being a 10 Mega Ohms resistor 8 and C a 0.15 microfarad capacitor 9. To protect a high back EMF voltage from damaging the timing integrated circuit LM555 7, a switching diode IN4148 6 is used.

The circuit is designed that each time the power supply line cable 1 is interrupted the relay 5 will not latch until a period of two to three seconds later.

1. A delay switching system is a device intended to provided a two to three seconds delay duration for the magnetic clutch of the air-conditioner compressor unit to switch on after the electric fan of the forced air cooling system of the condenser unit is switched on.

2. The delay switch on effect of the magnetic clutch of the air-conditioner compressor unit segregates the loading of the electrical system and the engine.

3. A delay switching system as claimed in claim 1 wherein the device switch-on delay is functioning each time the thermostat cut into service when the temperature is above the desired setting level.

4. The delay switching system as claimed in claim 2 wherein the effect reduces the high current surge on the electrical system as the load between the magnetic clutch of the airconditioner compressor unit and the electric fan of the forced air cooling system of the condenser unit is divided proportionally.

5. The delay switching system as claimed in claim 3 wherein the reduction of the high current surge means an improvement on the durability of the vacuum switch and/or auto relay (engine idle rpm air-conditioner cut-off control device), the thermostat, the alternator and the battery.

6. The delay switching system enables the

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Delay switching system This invention relates to a delay switching system for motor car air-conditioner system. Air-conditioner compressor units in motor cars are well known for its loading on the engines with major stress at the time that the compressor goes in service. The standard electrical/electronic control devices in a car air-conditioner system comprises of a blower fan switch, thermostat, electrical controlled magnetic clutch compressor unit and a vacuum and/or auto relay switch (engine idle rpm air-conditioner cut-off control device). Forced air cooling system for the car airconditioner system are normally driven by an electric fan and/or a direct mounted fan blade driven by the car engine to cool the condenser unit. Forced air cooling system that operates on the electric fan is generally wired with the magnetic clutch compressor unit. This electrical connection configuration will cause a severe loading on the engine as well as the overall electrical system at the time the airconditioner system is triggered on. The purpose of this invention is to improve the air-conditioner system through reducing the loading at the time the air-conditioner system is triggered on. This is achieved through a basic concept of sequential loading of the air-conditioner system by segregating the loading effects of the forced air cooling fan of the condenser unit and the magnetic clutch compressor unit. The sequential loading process is carried out by the "Delay Switching System" through its function of causing a switch-on delay effect of two to three seconds duration on the magnetic clutch compressor unit after the electric fan for the forced air cooling system of the condenser unit is switched on. The operation of the "Delay-Switching System" is to provide a repeated cycle of thetwo to three seconds switch-on delay duration for the air-conditioner compressor unit after the forced air cooling fan is switched on each time the thermostat cut into service when the temperature is above the desired setting level. A specific embodiment of the invention will now be described by way of the example with reference to the accompanying drawing in which: Figure 1 shows the standard electrical connection of the motor car air-conditioner system; Figure 2 shows the revised electrical connection of the motor car air-conditioner system using the "Delay Switching System"; Figure 3 shows the electronic circuitry of the "Delay Switching System"; Figure 4 shows the printed circuit board layout circuitry; and Figure 5 shows the component placement on the printed circuit board. Referring to the drawing the "Delay Switching System" comprises of a 3 cable lead-out connection, viz the negative cable 3 for the car chassis, the positive cable 1 to be connected to the incoming positive supply line of the battery which in this case it is taken from the original termination to the magnetic clutch of the air-conditioner compressor unit and in replacement the magnetic clutch of the airconditioner compressor unit is connected to the delayed switch lead-out cable 2 (output). The purpose of the 3 cable termination design of the "Delay Switching System" is to enable easy installation as well as to facilitate available electrical connection so as to eliminate unnecessary drawing of new cables to support the "Delay Switching System". In order to provide isolation between the incoming positive supply line of the battery and the delayed switch lead-out (output), a relay 5 is used. The timing sequence is processed by a RC network, i.e. R being a 10 Mega Ohms resistor 8 and C a 0.15 microfarad capacitor 9. To protect a high back EMF voltage from damaging the timing integrated circuit LM555 7, a switching diode IN4148 6 is used. The circuit is designed that each time the power supply line cable 1 is interrupted the relay 5 will not latch until a period of two to three seconds later. CLAIMS

6. The delay switching system enables the air-conditioner system to be left in the active mode (the air-conditioner system is electrically switched on but the engine is not running) at the time of starting up the engine without straining the engine as the engine does not take up the compressor unit load in lieu of the two to three seconds delay switch-on system.