JPS58123037A - Control circuit for fan convector - Google Patents

Abstract

PURPOSE:To enable an application of transistor having a low electric power make a small sized and less expensive circuit by a method wherein a circuit arrangement around the transistor turning on or off an energization of a relay controlling a load is devised. CONSTITUTION:Since a voltage at the input terminal 42b of a voltage comparator 42 corresponding to an output of a thermosensitive element 10 with a coefficient of load when a temperature is low is higher than a reference voltage at an input terminal 42a, the output 42c of the comparator 42 is L level and the transistor (Tr) 35 is turned on. In turn, when the temperature is higher up to a predetermined value, the output 42c of the comparator 42 becomes H level and Tr 35 is turned off. Then, a voltage between a collector and an emitter of Tr 35 shows a divided voltage area between the resistor (R) 33 and a relay coil resistor, so that the relay 34a is turned on, its contact point is closed and a fan convector not shown is started to operate. With the foregoing, it is possible to apply a transistor having a smaller standard than that of Tr 35.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control circuit for a fan convector.

The configuration of the present invention is a diode on one side of the commercial power supply.

The purpose is to connect a circuit in which a resistor and a relay coil are connected in series, a resistor and a capacitor are further connected in series7, and a transistor collector and emitter are connected in parallel to this series circuit, and then connected in parallel to the above relay coil. .

A conventional example is shown in FIG. In FIG. 1, 1 is a commercial power supply, 2 is a diode, the power supply side is an anode, the other end is a nine-sode, 3 resistors are on the cathode side, 4 is a relay, and the coil 4a is connected to the resistor. A transistor 6 is connected to the coil, with 6a being the emitter, 6b being the base, and 6 being the emitter.
C is the collector.

6 is a capacitor, 7 is a capacitor, 8 is a diode, 9
1o is a variable resistor, 1o is a temperature sensing element (thermistor) having a negative temperature coefficient, 11 is a constant voltage diode, 12 is a voltage comparator, and an inverting input terminal 12a.

In-phase input terminal 12b, output terminal 12C9 power supply 12d.

It has six elements (12+5). 13 to 21 are resistors.

In general, when controlling temperature, semiconductor elements are used and it is unlikely that loads are connected to relay contacts like in this example, but when controlling multiple loads at once, or if a common ground is If this is not possible, a relay contact may be used.

Semiconductors are used because the temperature is controlled. In this case, semiconductors cannot be used unless DC is used. There is a method of using a transformer to step down and rectify the voltage on the secondary side to obtain direct current, but this method has problems in terms of cost.

Therefore, the circuit shown in FIG. 1 has been widely used in the past. Rectify with diode 2 to obtain direct current. The problem with this circuit is that the voltage on the cathode side a of the diode 2 changes significantly.

For example, if a DC 24 type is used for the relay 4, a current of several IQm flows through the relay.

On the other hand, the current flowing through the control circuit is several millimeters, and the voltage at point a changes significantly between when the transistor 6 is on and when the transistor 6 is off. For this reason, the voltage across the resistor 13 changes significantly, requiring large power consumption.
Since a large current flows through the circuit, a large power type is required, which may result in a large cost or space requirement.

The present invention aims to improve these drawbacks, and one embodiment of the present invention will be described below with reference to FIG. 2.

In Fig. 2, 31 is a power supply, 32 is a diode, and 33 is a power supply.
is a resistor, 34 is a relay, 3421 is a coil, 36 is a transistor, 362L is an emitter, 35b is a
35 Cld collector, 36 is a capacitor, 37 is a capacitor, 38 is a diode, 39 is a variable resistor, 40 is a temperature sensing element (temperature sensing element with a negative temperature coefficient) which is a sensor.
It works by feeling the warm air.

41 is a constant voltage diode, 42 is a voltage comparator, 421L
is an inverting input terminal, 42b is an in-phase input terminal, 420 is an output terminal, 42d and 42e are power supply terminals, and 43 to 52 are resistors. The fan contestor is equipped with a fan.

Now, if the temperature is low, the input terminal 4 of the voltage comparator 42
Comparing the voltages 21L and 42b, v42a and v42b, shows that v42b>v42a, so the output 42C is off due to the nature of the voltage comparator, so the voltage is the voltage determined by the resistors 44, 45.46. transistor 3
Since transistor 6 is turned on and in the saturation region, the voltage between its collector and emitter is extremely low, and the transistor has a switching action. Since this fail relay 34 is not operating because the voltage is below the operating voltage, its normally closed terminal and common terminal are closed.

Further, a half-wave voltage flows through the transistor, and a current limited by the resistor 33 flows.

Next, when the temperature rises, v42b<v42a, so the output 420 is turned on and the voltage V420 is low. Therefore, the pace voltage V3sb of transistor 36
does not exceed the operating voltage, the transistor 36 turns off, and the voltage between the collector and emitter becomes the voltage divided by R54 and the relay coil resistance, and becomes an interruption region, so the relay 3
4 is turned on and its normally open terminal and common terminal are closed. The voltage at point b changes little in each state.

Therefore, the resistance 43 can be easily selected. Further, the transistor 35 can be used with a force rating that is the same or one size smaller than that of the conventional example. In the conventional example, a transistor is connected in series with the relay, so a fairly large transistor is required.

If you want to obtain the same output characteristics as the conventional example, you can use the opposite contacts.

As described above, according to the present invention, the following effects can be obtained.

(1) Transistors can be made smaller, making them cheaper and easier to use;

(2) The power of resistors that can be made smaller and cheaper;
1 Possible 0 (3) Space saving is possible.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a conventional example, and FIG. 2 is a circuit diagram of a control circuit for a fan compector in an embodiment of the present invention. 32...Diode, 33...Resistor,
34 &... IJL/- coil, 62...
・Resistance, 36... Concern answer, 36...
・Transistor.

Claims (1)

[Claims] A diode, a resistor, and a relay coil are connected in series to one side of the power supply, and a resistor and a capacitor are further connected in series, and a circuit in which the collector and emitter of a transistor are connected in parallel to this series circuit is connected in parallel to the relay coil. A control circuit for a Sulfuran compector that controls the load using relay contacts.