DE29812069U1 - Semiconductor relay for contactless switching of electrical consumers - Google Patents

Description

Dieter LEBER / Im Heidewinkel 19 D-912p7;LaLTf: CTd.: +'49^)8123-9860-80 Fax.:-82

Description Semiconductor relay for contactless switching of electrical consumers

State of the art

A contactless semiconductor relay does not have mechanically moving contacts as switching elements, but rather it typically switches the power using one of the following electronic switching elements:

- Triac

- antiparallel thyristors

- Switching transistor

- Power MOS-FET

- IGBT

The switching element is usually controlled by a much smaller control voltage. Typically, the control is optogalvanically isolated from the power unit.

Contactless semiconductor relays are mainly used in industrial electronics due to their wear-free nature.

The different manufacturers, e.g.

CRYDOM, general catalogue 1997, model HD4875 CARLO GAVAZZI, general catalogue undated, model RA 60 90 -D 16

offer their products with 3 different switching properties:

- Zero point switching

This type of switching is only used in alternating current networks. After the control voltage is applied, the relay only switches on when the current mains voltage just crosses the zero point or is in a small window around the zero point. This type of switching ensures that harmonics are particularly low.

- Momentary switching

This type of switching is used in both AC and DC networks. The relay switches on immediately after the control voltage is applied.

- Maximum switching

This type of switching is only used in alternating current networks. The relay switches on after the control voltage is applied when the current mains voltage is at its peak. With this type of switching, inductors can be switched on particularly gently and largely free of inrush current.

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Dieter LEBER / Im Heidewinkel 19 D-§12p7:Laaf j 'TgL; &eegr;»49£(0)&Rgr;1 23-9860-80 Fax.:-82

The switching off property results from the switch technology used and is roughly divided into

- OFF in next zero crossing of the current

- OFF immediately after the control is removed, but are not further important here.

The different switching characteristics mentioned above are achieved by different internal electronics.

Typically, all internal components of such a semiconductor relay are internally encapsulated or at least hermetically sealed so that only the four connection terminals of the semiconductor relay are accessible.

The disadvantages of the known semiconductor relays are:

- For each of the different switching characteristics, individual internal electronics must be developed, manufactured and kept in stock.

- If additional features are required, either additional special internal electronics must be developed or an additional module must be mounted separately to provide the additional features. Both options are very costly or require additional space in the control cabinet and additional wiring.

The invention specified in claim 1 is based on the problem of designing a semiconductor relay in such a way that it

- only internal electronics are used

- the various functional properties of the relay can be subsequently ‘plugged in’ using an additional component.

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Dieter LEBER / Im Heidewinkel 19 D-g12D7:Lauf: :&Tgr;6&Igr;.: *49ffl)Ei33-9860-80 Fax.:-82

These problems are solved with the features listed in claim 1 as follows:

- The internal electronics are universally oriented. They prepare all the information that can be observed in a semiconductor relay and offer it to the module to be plugged in. Drawing 1 describes a possible universal electronics.

- The component to be plugged in can be a programmable micro-controller, e.g. model PIC 16C71 from MICROCHIP.

- The module to be plugged is inserted into a socket.

- The internal electronics are designed in such a way that the socket is accessible from the outside of the semiconductor relay, thus allowing the programmed module to be plugged in at any time.

- The required switching functions and properties of the relay are only determined by the internal programming or by the program of the module to be plugged in.

- This component is only inserted shortly before the semiconductor relay is used and thus determines the overall function of the semiconductor relay.

- This module can be programmed so universally that new, innovative, customer-specific functions can be packed into the semiconductor relay, such as:

- Soft start using phase control

- Burst firing with optimally distributed half-waves within a control period

- Control via serial telegram

- Preheating of the load after a cold start through initial soft start from 0-100% within e.g. 0.5 seconds

- Use of the second input for locking

- Error Condition Freezing, before the main voltage is switched off, -etc.

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Dieter LEBER / Im Heidewinkel 19 D-g1 ZO?. LaOfI^ITfel.: -&Mgr;£&Ggr;-{6%&idiagr;23-9860-80 Fax.:-82

drawings

Drawing 1 shows a typical circuit diagram of an AC switch with two anti-parallel thyristors and a possible variant of universal internal electronics, here with 2 control inputs and an alarm output:

The two controls (1) and (2) can be seen, each of which goes to an adaptation stage (4). The plug-in and programmable component (6), which is plugged into the socket (13), controls the adaptation stages (4) in such a way that different control signals can be processed, such as:

- active control with e.g. 24V DC

- passive control with potential-free contact or an open collector transistor

- analog control 0 .. 10V

- analog control 0 .. 2OmA,

The two inputs can also be operated mixed.

The plug-in and programmable component (6) can switch on the two anti-parallel thyristors (11) and (12) using the optocoupled and opto-isolated triac (7). At the same time, it can monitor the ignition current, which must occur once in each half-wave, using the optocoupled and opto-isolated transistor (8). While the semiconductor relay is not switched on, the plug-in and programmable component (6) continuously monitors the network using the optocoupled and opto-isolated transistor (9). In addition, the plug-in and programmable component (6) can monitor the internal temperature (10) of the semiconductor relay. Finally, the plug-in and programmable component (6) can control an auxiliary relay (5) or drop it out, thereby reporting a fault to the outside (3).

Figure 2 shows a typical solid state relay from above.

The two connections (14) of the electronic switch can be seen, as well as the socket strip (21) for a screw-on connector, as is typically used. The base (13) can also be seen, which protrudes from the semiconductor relay and into which the programmable component (6) can be plugged.

The design of the semiconductor relay shown here is not mandatory and can be varied as desired. Other designs of plug-in components instead of the dual-in-line housing shown here are also conceivable.

Also, the base 13 does not have to protrude from the top of the semiconductor relay, but can be led out at any point.

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Claims (1)

Dieter LEBER / Im Heidewinkel 19 0-31207IaUf I ITeS.: +n9-*(tE)9123-9860-80 Fax.:-82 Claim for protection Semiconductor relay for contactless switching of electrical consumers, characterized by that the internal function of the relay is solved with a programmable electronic circuit with the necessary peripherals and that the programmed circuit must be inserted into a socket and that the arrangement of the components is chosen in such a way that the socket on one side of the semiconductor relay is accessible from the outside, so that the programmable electronic circuit can be plugged in or even replaced with another one at any time. V1.0 (03.07.98) Page-1- C:la\ID\Patent\Patent_01.doc