JPS5813499Y2 - Record player Yanioker Stroboscope display - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a stroboscope illumination device used for illuminating a stroboscope provided on the turntable of a record player to clearly display a striped pattern.

In a stroboscope, the clarity of the striped pattern depends on the duration of the brightness change of the light source used and the temporal length of the light emission.

As a light source, neon tubes are the most widely used, which have many advantages in terms of usage conditions, but neon tubes have many advantages, for example 100V.

When connected to a 50 Hz power source via a resistor, the generation time is as long as 6 to 7 m5 ec, and when used for illumination of a stroboscope installed on the turntable of a record player, the boundaries of the striped pattern become unclear.

This invention aims to provide an illumination device that can clearly show the striped pattern of a stroboscope and improve measurement accuracy and usability.

An embodiment of this invention will be described with reference to the drawings.

In Fig. 1, the double-wave rectifier circuit constituted by diodes D1 to D4 is for rectifying commutation from a 1ooV15゜Hz AC power supply, and its rectified output voltage (
Approximately 140 V) is applied across a series circuit consisting of a resistor R1, a neon tube Ne, an h transistor Tr, and a diode D5.

Note that C1 and R2 represent a capacitor r and a resistor connected in parallel with this series circuit.

A diode D6 is connected to the output terminal of the double-wave rectifier circuit in the forward direction with respect to the output current in order to obtain a peak value from the output of the double-wave rectifier circuit at both ends of the first capacitor→J-CI.

A voltage corresponding to the pulsating output of the double-wave rectifier circuit is applied between the base of the transistor Tr and the other output terminal of the double-wave rectifier circuit, and a charging current is applied to the base of the transistor. a second continuum +rC that turns the transistor on and off in accordance with the cycle of the AC power supply current;
2 are connected.

Further, a resistor R3 for turning off the transistor Tr when there is no signal is connected between the base and emitter of the transistor between the connection point and the emitter of the transistor base and the second capacitor C2, and the double-wave rectifier circuit A resistor R4 is connected between the positive side of the capacitor +ic2 and the second capacitor +ic2.

Figure 2 shows the pressure waveform diagram of each part of the circuit in Figure 1.
a is the pulsating voltage waveform at point a of the rectified output of the double-wave rectifier circuit, b is the voltage waveform at the point on the base side of the transistor, C is the voltage waveform at point C on the collector side of the transistor, and d is the power supply of the first capacitor C1 This is the voltage waveform at point d on the side.

3 and 4 are circuit diagrams showing the relationship between point a and point d in FIG. 1.

The embodiment of this invention has the structure shown in FIG. 1 above, and its operation will be explained below with reference to FIG. 2 and FIG. 4.

A peak value shown in FIG. 2d is obtained at both ends of the first capacitor C1, and a voltage as shown in FIG. 2a is obtained at point a.

Now, to describe the relationship between point a and point d in Figure 1,
As shown in FIGS. 3 and 4.

That is, in order to explain its function and configuration, if we omit the neon tube Nez current control resistors R1 and R3, diode D5, and capacitor C2, which are the loads of the trundle leg transistor T r z , the result is as shown in Fig. 3. , except for the period when the charge-up current of C1 flows, the point a and the ground GND are separated by the diode D6, resulting in the configuration shown in FIG. 4.

Therefore, the voltage at point d is approximately constant plus 140V, and point d has a voltage waveform as shown in a in FIG. 2 with plus 140V as a reference.

Then, the pulsating voltage at point a (Fig. 2 a) charges the second capacitor C2 for controlling the base potential of the illustrated transistor Tr, and generates a voltage corresponding to the pulsating voltage at point a at the base of the transistor. do.

Here, by selecting the values of the resistor R3 and the resistor R4, the charging current of the second capacitor C2 is limited and the peak value of the potential applied to the base of the transistor Tr is controlled.

Then, the potential applied to the base of the transistor Tr (second
When the threshold level Vbe between the base and emitter of the transistor Tr becomes 2Vbe or more, the sum of the threshold level Vbe and the threshold level Vbe of the transistor D5 becomes 2Vbe or more, the transistor Tr is turned on and the charge charged in the first capacitor C1 becomes the first The neon tube Ne is turned on by discharging in the path of capacitor C1-resistor R1-neon tube Ne-transistor Tr-diode D5-first capacitor C1.

On the other hand, the second capacitor C2 continues to be charged until the pulsating voltage at point a reaches its peak value, but when it exceeds the peak value and begins to decrease, the second capacitor C2 follows this and sequentially charges the second capacitor C2. C
2 charge is from capacitor C2-point a-diode D3
- Power supply (not shown) diode D1 - Resistor R2 - Resistor R3
- The path of capacitor C2 discharges and its charging voltage decreases.

When the base potential of the transistor Tr falls below 2Vbe following this decrease in the charging voltage of the second capacitor C2, the transistor Tr is turned off and the neon tube Ne is turned off.

That is, during the period when the voltage at point B is 2Vbe or more, the transistor Tr is turned on and the neon tube Ne is lit.

Then, when the next rectified waveform becomes and the potential at point a starts to increase, the base potential also increases through the second capacitor -+t-C'l, and when the potential becomes 2Vbe or more as above, the transistor Tr Turn it on again and the neon tube Ne lights up.

Thereafter, the above operation is repeated for each rectified waveform, that is, corresponding to the cycle of the power supply voltage, and the transistor Tr is controlled on and off to cause the neon tube Ne to blink periodically.

Furthermore, by turning on and off the transistor Tr, a pulse voltage (FIG. 2C) corresponding to the cycle of the power supply voltage is obtained at the 0 point.

Therefore, according to this invention, it is possible to light up the neon tube Ne precisely for a predetermined period of time according to the cycle of the power supply voltage, and even if the power supply voltage fluctuates, it has the characteristic that the fluctuation in the pulse width is extremely small. Become something.

Such a light source can clearly display the striped pattern of the stroboscope, maximize the functionality of the stroboscope, and give a pleasing visual impression.

Moreover, this invention does not require a transformer, which is indispensable for other pulse generation circuits, and the overall circuit configuration is simple, so it can be configured extremely compactly.
Not subject to restrictions on installation conditions.

[Brief explanation of the drawing]

FIG. 1 is an electrical circuit diagram of a lighting device according to an embodiment of the invention, and FIG. 2 is a graph showing voltage waveforms at various parts thereof. 3 and 4 are circuit diagrams showing the relationship between points a and d in FIG. 1.

Claims (1)

[Scope of utility model registration request] a double-wave rectifier circuit for double-wave rectifying an AC power supply; a power supply positive electrode line connected to one terminal of the double-wave rectifier circuit;
A power supply negative line connected via a first diode D6 whose cathode side is connected to the other terminal of the double-wave rectifier circuit, and a first power supply line connected between the power supply positive and negative lines.
a neon tube driving means which connects in series a capacitor C1, a neon tube Ne connected between the positive and negative electrode lines of the power source, a transistor Trs, and a diode D5 whose anode side is connected to the emitter of the transistor Tr; A second transistor whose positive electrode side is connected to the other terminal of the double-wave rectifier circuit and whose negative electrode side is connected to the base of the transistor Tr, and which turns on and off the transistor Tr in accordance with the cycle of the pulsating output of the double-wave rectifier circuit. It consists of a capacitor C2 and a resistor R3 connected to the base of the transistor Tr and the negative electrode line of the power supply in order to apply a forward bias between the base and emitter of the transistor Tr.
A stroboscope illumination device for a record player, characterized in that the first capacitor +t-C1 is charged and discharged by turning on and turning off r.