DD152215A1 - DEVICE FOR TEMPERATURE CONTROL - Google Patents

Abstract

The invention relates to a device for temperature control and is preferably in Kopiergeraeten with Waermestrahlerfixierung use.Ihr the task is based on simple means to create a control loop, which ensures a multiple protection function. To erfindungsgemäaeszen solution of this problem it is provided that a motor for a ventilator is connected in series to the heat source of the device and a Termoschalter is parallel only to the engine in the circuit, wherein the Termoschalter is closed at normal temperature. The applicability is given on all devices with heat radiators, if possible on a dark radiator basis.

Description

Dresden, on 2. 7.1980 044

T itel of the invention

Device for temperature control

Use of the invention

The invention relates to a device for temperature control in devices with electrical heat source and is preferably used in copiers with heat radiator fixation use.

C characteristic of the known technical solution

It is widely known, as described for example in DD-PS 60 1b7, to use bimetal strips as actuators for switches. With the switches then either the heat source off or an additional fan switched on, as long as a certain limit temperature is exceeded. Thus, a two-point control is guaranteed; and only one simple protection function is triggered at a time.

Aim of the invention

The invention is based on the object to provide a control circuit with simple means that ensures a multiple Schutzfunlccion.

Darle supply of being s d e r invention

To solve this problem of the invention, it is provided that a motor for a fan is connected in series to the heat source of the device and a thermal switch is parallel only to the engine in the circuit arrangement. In an advantageous embodiment of the invention, the thermal switch itself is formed by a bimetallic strip, which assumes the switch closing position at normal temperatures.

.Execution example

The invention is illustrated and described in detail with reference to an embodiment. The graphic representation is based on a single figure. Accordingly, runs between the terminals 4 and 3

1> the device line circuit of the relevant line section, this is the engine Z for a fan in series with the heat source 3? For example, a Dunicelstrahler in the copier, switched. Continue to be located; but parallel only to the motor 2, a thermal switch 1 in the form of a bimetallic strip in the circuit, wherein the thermal switch 1 is closed at normal temperatures.

The function is very simple. When operating the heat source 3 of the device in the range of normal temperatures in the functional zone, the motor 2 from the parallel branch

2> short-circuited with the closed thermal switch 1, so that no current flows through the line section of the motor 2 and the full power for the operation of the heat source 3 is available. If now forms a heat flow, in which the permissible limit temperature is exceeded, opens thermo switch 1 by the bending of the bimetallic strip. As a result, now flows the current through the engine 2, because the KurζSuendüberbrückung has dropped away. As a result, the fan for bringing a Kühllu'tstromes is going on

set. In addition, but also reduces the performance of the heat source 3> because the internal resistance of the motor 2 affects the current. The degree of this reduction in performance is dependent on the design of the internal resistance of the Mcncors 2 and can be brought as far as required, aaü a heating a heat source 3 practically hardly ever done;

Thus, a double effect in the l'emperaturregelung is achieved by simple means, whereby a 1U faster overcoming the inadmissible increase in temperature is guaranteed.

Claims (2)

Erf indungsan sp smell 1. A device for controlling the temperature of devices with electrical heat source, preferably in copiers with heat radiator fixation using thermal circuit, characterized in that a motor (2) for a fan in series with the heat source (3) of the device is switched and the thermal switch (1) is parallel only to the motor (2) in the circuit arrangement. 2. Device according to item 1, characterized in that the thermal switch (1) itself is formed by a bimetallic strip.