JPH043553Y2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Field of Industrial Application The present invention relates to secondary battery applied devices such as electric shavers that use small motors, and relates to their charging and motor drive circuits.

(b) Prior art As an example of this type of charging device, for example,
There is a publication number 11935.

In this example, the PUT gate circuit is directly connected to the secondary coil, so the PUT turns ON and OFF regardless of whether the start switch is opened or closed. Therefore, the PUT gate circuit is connected to the secondary coil directly, so the PUT turns ON and OFF regardless of whether the start switch is opened or closed. Since the outputs are the same, there is a problem in that when the secondary coil outputs are combined when driving a load, the charging current supplied to the battery becomes too large.

(c) Purpose of the invention The present invention was developed in view of the problems of the prior art as described above. This prevents charging.

(d) Configuration of the device: An inverter circuit consisting of a rectifier that rectifies AC input, an oscillation transistor, and a transformer;
a series circuit including a battery to be charged connected to the secondary coil of the transformer via a diode, a load and a starting switch connected in parallel to the battery;
A group of resistors connected in series to both poles of the load and a bias of the inverter circuit are controlled.
The gate of the PUT is connected between the resistor group, the anode is connected to the primary coil of the transformer, and the cathode is connected to the feedback coil of the transformer, and a large current is generated when the PUT conducts. A small current flows to drive the load, and when the PUT is cut off, a small current flows to charge the battery.

(E) Example An example in which the present invention is applied to an electric circuit of an electric shaver will be described below.

First embodiment AC and AC are AC input terminals, Re is a bridge rectifier that rectifies the AC input from the AC input terminals AC and AC, and C1 is a noise prevention device that smoothes the DC output rectified by the rectifier Re. Capacitor, N1
is the primary coil of the transformer T connected in parallel to the capacitor C1, and C2 is the primary coil N1.
Q1 is a common-emitter transistor whose collector is connected to one end of the primary coil N1, and N2 is the transistor Q
Feedback coil connected to the base of 1, C3, R1
are a capacitor and a resistor connected in parallel to one end of the feedback coil N2, and these components form an inverter circuit.

N3 is a secondary coil of the transformer T, B is a battery to be charged such as a Ni-Cd battery connected via a rectifying diode D connected to one end of the secondary coil N3, and M is a battery for the battery B. S is a starting switch connected to one end of the motor M; R4 and R5 are a pair of resistors connected to both poles of the motor M to form a resistance group;
P is a PUT (programmable union transistor) having a gate connected to the midpoint between the resistors R4 and R5, an anode connected to the primary coil N1 via the resistor R2, and a cathode connected to the feedback coil N2. ), and the anode and cathode are short-circuited via a resistor R7, and the anode is also connected to an inverter circuit via resistors R8 and R3.

N4 is an auxiliary coil of the transformer T, and the auxiliary coil N4 has a light emitting diode for displaying charging.
LED is connected.

Next, the operation of this circuit will be explained. During charging, the start switch S is in an open state, and when an AC power source is connected to the AC input terminal, the inverter circuit starts oscillating operation by the transistor Q1, and a current is induced in the secondary coil N3. By the way, since the starting switch S is in an open state, the gate voltage of PUT (P) is high and PUT (P) is OFF. Therefore, the current flows from resistor R2 → resistor R7 → feedback coil N2
As a result, the bias resistance of transistor Q1 increases and the output of secondary coil N3 decreases. Therefore, the charging current for the battery B to be charged becomes a small current, and damage to the battery B can be prevented.

When the start switch S is closed, the gate voltage of PUT (P) decreases and PUT (P) turns ON.
Therefore, current flows from the output of the bridge rectifier Re through the resistor R2 to the feedback coil N2, the bias resistance of the transistor Q1 is small, and the output of the secondary coil N3 becomes large, which is suitable for driving the motor M.

Second Embodiment FIG. 2 shows a circuit of a second embodiment. In this example, a switching transistor Q2 is used in place of the starting switch S of the first embodiment. An IC (I) is connected to the base of this transistor Q2, and the base voltage of the transistor Q2 is controlled by the output of this IC (I) using switches S1 and S2, thereby controlling the drive of the motor M. It is something.

The anode of PUT (P) is connected to the midpoint of a voltage divider circuit consisting of a resistor R6 and a resistor R8, and a Zener diode ZD is connected in parallel with the voltage divider circuit to stabilize the operating voltage of the IC (I). Connected.

(f) Effects of the invention According to the charging device of the invention, the starting switch is
When turning ON to drive a load, PUT is ON.
This increases the feedback current to the inverter circuit, increasing the output of the secondary coil and allowing a large current to be supplied to the load.At the same time, when the starting switch is turned off and the battery being charged is charged, PUT is turned off and the transistor is turned off. Since the base bias resistance increases and the secondary coil output decreases, the current supplied to the battery to be charged becomes small. As described above, the present invention has the effect of being able to supply the optimum current to the load when the load is used, and to the battery to be charged when charging the battery.

[Brief explanation of drawings]

Figure 1 is an implementation circuit diagram of the charging device of the present invention;
The figure also shows another implementation circuit diagram. Re... Rectifier, Q1... Transistor, T...
...Transformer, N3...Secondary coil, D...Diode, B...Battery to be charged, M...Load, S, Q2
...Start switch, R4, R5...Resistance group, P...
...PUT, N2...Feedback coil.

Claims (1)

[Scope of utility model registration request] an inverter circuit consisting of a rectifier that rectifies AC input, an oscillation transistor, and a transformer;
a series circuit including a battery to be charged connected to the secondary coil of the transformer via a diode, a load and a starting switch connected in parallel to the battery;
A group of resistors connected in series to both poles of the load and a bias of the inverter circuit are controlled.
1. A charging device comprising a PUT, the gate of the PUT being connected between the resistor groups, the anode being connected to the primary coil of the transformer, and the cathode being connected to the feedback coil of the transformer.