JPS6157687B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a plunger solenoid drive circuit that can drive a plurality of plunger solenoids individually.

In general, a plunger solenoid attracts and repulses an iron core by applying electricity to a coil held in a yoke, and the movement stroke of this iron core causes the required mechanical operation of other drive mechanisms. The force required to start the iron core is different from the force required to hold the iron core in a predetermined position after activation.
The amount of current applied to the coil is also controlled in consideration of power consumption, so the solenoid drive circuit is configured to control this amount of current.In conventional drive circuits, the power source for energizing the plunger solenoid and the power source for the drive circuit are connected. are separate from each other, requiring at least two power supplies and the same number of drive circuits to drive each of the plurality of solenoids separately. It has the following drawbacks.

The present invention aims to eliminate such drawbacks by using a common power source for energization and a common power source for the drive circuit, and also using a common drive circuit for each positive gear solenoid.

Hereinafter, this invention will be explained in detail with reference to an embodiment shown in the drawings.

That is, in the drawings, S ₁ to _{S 3} are drive signal introduction ends of the plunger solenoid, and the following explanation will explain the configuration and operation of the drive circuit when this drive signal is introduced to the first terminal S ₁ . do.

First, when a high voltage level drive signal is introduced to terminal S ₁ , the signal voltage is divided by resistors R ₁ and R ₂ , and the divided signal voltage is used to drive the transistor.
Q ₁ is made conductive and capacitor C ₁ is charged from the power supply +B through resistor R ₃ . At this time, transistor Q ₁ suddenly becomes conductive, and its collector voltage drops from the power supply voltage to ground potential, so the voltage at the connection point between capacitor C ₁ and diode D ₁ drops rapidly, and the next stage transistor Q ₂ The base voltage of Q2 also decreases, and this transistor _Q2 becomes non-conductive. On the other hand, the drive signal introduction terminal _S1 is connected to the base of the transistor _Q6 via the resistor _R7 , so when the above signal is introduced to the terminal _S1 , the transistor _Q6 becomes conductive. collector voltage,
Immediately, the base voltage of transistor _Q7 decreases, and this transistor _Q7 also becomes conductive.

Here, as the transistor Q ₂ becomes non-conductive as described above, the base voltage of the transistor Q ₄ increases, and this transistor Q ₄ becomes conductive, and as a result,
The voltage of the power supply +B is applied to the plunger solenoid via the collectors and emitters of transistors Q ₄ and Q ₇ .
is applied to PL, and this solenoid PL is driven. Then, charging of capacitor C ₁ progresses, and when it exceeds a certain charge level, transistor Q ₂
The base voltage of also increases, this transistor Q ₂ becomes conductive and then transistor Q ₄ becomes non-conductive. (The period during which transistor Q ₂ is non-conducting depends on the charging speed of capacitor C ₁ , and the charging speed depends on the time constant of the charging/discharging circuit made up of resistor R ₃ and capacitor C ₁ . Because it will be done,
By setting the values of resistor R ₃ and capacitor C ₁ appropriately, the activation time of the plunger solenoid can be determined. ) However, the collector of the transistor _Q5 is always applied with the power supply voltage from the power supply +B, and the capacitor _C2 is charged with the power supply voltage through the resistor _R6 , which is regulated by the Zener diode _ZD1 . Therefore, when transistor Q ₇ conducts, the emitter voltage of transistor Q ₇ , immediately, transistor Q ₅
The emitter voltage of Q5 decreases and transistor _Q5 becomes conductive.

That is, as long as the drive signal is applied to the terminal S ₁ , the transistors Q ₆ and Q ₇ always maintain a conductive state, so the transistor Q ₅ remains conductive, the transistor Q ₂ conducts, and the transistor Q ₄
Since transistor _Q5 is conducting even though it is non-conducting, the power supply voltage +B is a Zener diode.
Plunger solenoid via transistor Q ₇ with holding voltage regulated by reverse voltage of ZD ₁
Applied to PL.

That is, when a drive signal is not applied to terminal S ₁ , both transistors Q ₄ and Q ₅ are non-conductive, so no current is applied to solenoid PL, but when this signal is applied to terminal S ₁ , no current is applied to solenoid PL. Then, both transistors Q ₄ and Q ₅ become conductive, and a large voltage, i.e., a starting voltage, is applied to the solenoid PL. Then, after a predetermined period of time, when transistor Q ₄ becomes non-conductive, transistor Q ₅ becomes conductive. A voltage regulated by the Zener diode ZD ₁ , that is, a holding voltage, is applied to the solenoid PL via the solenoid PL.

Here, the capacitor _C2 functions as a filter to remove ripple components and the like in order to flatten the holding voltage level.

Next, blocks A' and A'' have the same circuit configuration as block A, and block the drive signal.
By applying voltage to the terminal S ₂ or S ₃ of A' or A'', respectively, the common drive circuit is operated in the same manner as described above to drive the plunger solenoids PL ₂ and PL ₃ .

That is, for example, when a drive signal for the solenoid PL2 is applied to _S2 , in the block A', the transistor _Q'1 corresponding to the transistor _Q1 of the block A changes to the capacitor _C'1 corresponding to the capacitor _C1 of the block A. While being charged, the transistors Q' ₆ and Q' ₇ corresponding to the transistors Q ₆ and Q ₇ of the block A are also turned on. and,
Solenoid PL2 applies the starting voltage to each solenoid from the +B power supply while the above transistor _Q'1 is on.
It is activated via the transistor _Q4 common to PL1 to PL3 and the transistor _Q'7 in block A', and the transistor common to each solenoid is activated.
After Q ₂ is turned on and the transistor Q ₄ is turned off, the holding voltage regulated by the Zener diode ZD ₁ common to each solenoid PL1 to PL2 is applied to the transistor Q ₅ and the transistor Q' common to each solenoid PL1 to PL2. ₇ to maintain operating status.

The circuit configuration and operation of this invention are as described above, but here we will show how the above-mentioned drawbacks of conventional circuits have been eliminated and clarify the effects of this invention. First of all, In this invention, the driving power source for the solenoid and the power source for its driving circuit are commonly used, and thus, in this invention, it is possible to cover everything with only one type of power source.

Second, this invention does not require the same number of drive circuits for multiple solenoids; only a portion of the drive circuits are provided corresponding to the number of solenoids; most of the drive circuits are Since they can be used in common, the circuit configuration can be simplified and the number of parts used can be significantly reduced.

In this way, according to the present invention, the intended purpose can be achieved.

In addition, the starting voltage level of the solenoid is large,
Although the holding voltage level is small, the starting voltage level is held at a constant level, and the holding voltage level is also held at a constant level, but the holding voltage level can be set at any time by connecting multiple Zener diodes in series. It should be obvious that it can be done.

[Brief explanation of the drawing]

The drawing shows an embodiment of the drive circuit according to the present invention, and in the drawing, S ₁ to _{S 3} are driving signal introduction terminals of solenoids, and PL ₁ to _{PL 3} are solenoids.

Claims (1)

[Scope of Claims] 1. A device comprising a plurality of plunger solenoids and a plurality of drive transistors for driving these plunger solenoids, and a desired drive transistor is selected based on a plunger drive signal corresponding to each of the plunger solenoids. A desired plunger solenoid is driven by turning on a common power supply voltage source, and each of the plunger solenoids is provided with a first switching means that operates for a predetermined period of time based on each of the plunger drive signals. a second switching means capable of supplying a starting voltage from the power supply voltage source to the desired plunger solenoid for the predetermined period of time when the first switching means is turned on; A third switching means capable of supplying a holding voltage from the power supply voltage source is provided in common to each of the plungers and solenoids, and when a desired driving transistor is turned on based on the plunger drive signal, the first switching means is turned on. During the predetermined period of time that the transistor is turned on, the desired driving transistor receives the starting voltage via the second switching means to start the desired plunger solenoid, and after the elapse of the predetermined period of time, the desired driving transistor continues to operate. A driving circuit for a plunger solenoid, wherein the driving transistor receives the holding voltage via the third switching means to maintain the desired plunger solenoid in an operating state.