US3461343A - Simplified low voltage controlled neon bulb circuit and method of operating - Google Patents

Description

Aug. 12, 1969 G. WINTRISS 3,461,343

SIMPLIFIED LOW VOLTAGE CONTROLLED NEON BULB CIRCUIT AND METHOD OF OPERATING Filed March 4, 1966 2 Sheets-Sheet l .llhfllll m I6 5 PULSDAEING 0 eENER'Ai'oR 34JPO'I5OV. +0 I le' g E i/ c'l6 f INVENTOR Mm QM Aing. I2; 1969 a. wm'rms's 3 3 SIMPLIFIED LOW VOLTAGE CONTROLLED NEON BULB CIRCUIT AND METHOD OF OPERATING Filed March 4, 1966 2 Sheets-Sheet 2 FIG. 2. s m M i United States Patent 3,461,343 SIMPLIFIED LOW VOLTAGE CQNTROLLED NEON BULB CIRCUIT AND METHOD OF OPERATING Gaylord Wintriss, 16 Deborah Way, Fanwood, NJ. 07023 Filed Mar. 4, 1966, Ser. No. 531,959 Int. Cl. Hb 37/02, 39/04 US. Cl. 315-169 9 Claims ABSTRACT OF THE DISCLOSURE Summary of the invention This invention relates to electric circuits that contain neon bulbs, and more especially to such circuits in which the lighting of the of the neon bulbs is controlled by low voltage.

It is an object of this invention to provide an electric circuit with components operated on voltages lower than that required to light a neon bulb, and to connect a plurality of neon bulbs across the circuit with a pulsating voltage that cooperates with the low voltages of the circuit components to change the voltage on the bulbs above or below the bulb driving voltage depending upon the condition elsewhere in the circuit.

It is common practice to indicate the condition of an electric circuit, such as a flip-flop (Eccles-Iordan) multivibrator circuit of a computer, by the lighting of neon bulbs. Where transistors are used in the circuit, they operate on voltage that is substantially lower than the voltages required to light the neon bulbs and it has been necessary to add to the circuits special transistors of high voltage, these special transistors being known as neon drivers.

It is a more specific object of this invention to provide an improved electric transistor circuit with means for indicating the condition of the circuit by lighting neon bulbs without requiring the use of neon drivers. It may be said to be an object of the invention to simplify an electric transistor circuit by connecting neon bulbs with the transistors in such a way that low voltage transistors control the operation of the neon bulbs, and parts of the usual circuit can be omitted without omitting the function.

Another object is to provide an improved method for controlling an electric circuit having neon indicator bulbs.

Other objects, features and advantages of the invention will appear or be pointed out as the description proceeds.

Brief description of the drawing In the drawing. forming a part hereof in which like reference characters indicate corresponding parts in all the views:

FIGURE 1 is a wiring diagram for a flip-flop circuit embodying this invention;

FIGURE 2 is a wiring diagram similar to FIGURE 1 but showing both of the neon bulb indicators connected with only one of the transistor sides of the circuit; and

FIGURES 3 and 4 show other modifications of the invention.

Description of the preferred embodiments The circuits shown in the drawing includes two transistors 10 and 12 connected in parallel between the negative side of a battery 14 and grounding connections 16. A resistor 18 is connected in the circuit between the battery 14 and the collector of the transistor 10; and there is a similar resistor 20 connected in the circuit between the battery 14 and the collector of transistor 12.

Between the resistor 18 and the transistor 10, the circuit of that transistor is connected by conductor 21 and resistor 22 with the base of the transistor 12. There is a corresponding connection from the circuit of transistor 12, between its resistor 20 and that transistor connecting with the base of the transistor 10 through a conductor 23 and resistor 24.

Positive control pulses are supplied to the conductor 21 from a pulse circuit 26, and to the conductor 23 from a pulse circuit 28. A neon bulb 3%) is connected on one side to the circuit of the transistor 10 and a neon bulb 32 is connected on one side to the circuit of the transi tor 12. Both the neon bulbs 30 and 32 have their other sides connected at 37 with a common power source 34 through a resistor 36.

The power source 34 supplies a pulsating direct current which is of negative polarity for the circuit illustrated. By way of illustration, the voltage of the power source 34 is volts but the voltage goes to 0 or substantially to 0, at the end of each pulse of the cycle.

When the transistor 10 is conducting, and the other transistor 12 is non-conducting in accordance with the characteristics of a flip-flop circuit, the application of a positive signal pulse from the circuit 28 cuts off transistor 10 and turns on transistor 12. This is a stable condition and lasts until a positive pulse from the circuit 26 cuts off transistor 12 and turns on transistor 10.

When transistor 10 is conducting, the voltage on the transistor side of neon bulb 30 is substantially zero, and the voltage on the transistor side of neon b-ulb 32 i l2. As the voltage of power source 34 rises from zero (beginning a new cycle) the voltage at point 37 rises also; and at approximately 70 volts, and the neon bulb 30 fires. Neon bulb 32 cannot fire first, because it sees only 58 volts (70 less 12 v.=58 v.).

The voltage at point 37 then drops to approximately 55 v. (typical neon maintaining voltage) and remains there even as the voltage of power source 34 continues to rise to its peak and then subsides. Neon bulb 30 will remain on until the voltage at point 37 drops below approximately 55 volts, at which time it will extinguish. The same sequence of events occurs in each voltage cycle, as long as transistor 10 remains on.

Should the flip-flop change its state (transistor 10 off and transistor 12 on) the voltages appearing on the transistor side of the two neons bulbs are interchanged, and neon bulb 32 turn on in each cycle instead of neon bulb 30. Because of the fact that the current through the neon bulbs is low as compared to the current through the transistors, the neon bulb circuit will not interfere with the operation of transistors 10 and 12.

It is necessary however that the pulses from the power source 34 have a frequency which is correlated with the frequency of flip-flop operation. For example, the frequency of the pulsating direct current from the power source 34 must be high enough so that at least one cycle occurs during each of the flip-flop stable conditions.

It is not necessary to provide complementary voltages to the transistor sides of the neon bulbs as has been described, although this mode of operation requires a minimum voltage swing on each transistor. As an example, the transistor side of the neon bulb 32 could be disconnected from the junction of resistors 20 and 24, transistor 12 and pulse circuit 28 and connected to the negative side of a 12 volt battery; the positive side of which goes to ground.

Battery 14 must be changed to 24 volts. Having made these changes the neon bulbs will operate in a similar manner as previously described, while receiving only a single control voltage. FIGURE 2 shows the construction of FIGURE 1 with these changes. Corresponding parts of the structure are designated by the same reference characters with an a appended. The only added structure is a battery 44.

When transistor 10 is oif 24 volts will appear on the transistor side of the neon bulb 30. Starting from volts, when the voltage at point 37 reaches 82 volts the neon bulb 30 will see 58 volts (-82 les 24:58) and neon bulb 32 will see 70 volts (-82 less l2=70); thus neon bulb 32 will fire. When transistor is on, the transistor side of the neon bulb 30 is 0 volts. Starting from 0 volts, when the voltage at point 37 reaches 70 volts, neon bulb 32 will see -58 volts (70 less l2=58) and neon bulb 30 will see 70 volts (-70 less O=70); thus neon bulb 32 will fire.

In the preferred embodiment of the invention, the frequency of the pulsating voltage is high enough to give the neon bulb apparently continuous illumination when the bulb is to used as 'a visual signal, and when the bulb is to be used to control a light responsive device, the frequency is high enough to make dark periods of each cycle shorter than the response time of the [light responsive device.

It will be understood that the term cycle as used herein does not necessarily designate a symmetrical change in voltage. The pulsating direct current from the source 34 is preferably supplied with rectified half waves so that there are no iulls between pulses, but it can be supplied with power through a rectifier with no provision for using the positive half of the wave and in such cases the power supply from the source 34 supplies power only one half of the time. A cycle, as the term is used herein, is the operation of the power source 34 from. one condition to the same condition on the next repetition of the operation of the power source.

Although the invention has been described as applied to a multi-vibnator circuit, it should be understood that it is not limited to such circuits, nor is it limited to use with transistors. FIGURES 3 and 4 show the invention used with other semi-conductor devices 46 for any circuit where it is desirable that the components other than the neon bulbs operate on low voltage. Parts corresponding to the other figures are indicated by the same reference nuunerals but with a b appended in FIGURE 3 and a c appended in FIGURE 4. Ordinarily this low voltage is direct current but it can be pulsating or alternating if properly phased with the pulsating power supply to the neon bulbs. Using other than direct current for the low voltage components takes away some of the simplicity from the invention.

The preferred embodiment of the invention has been illustrated and described, and the invention as defined in the claims.

What is claimed is:

1. An electric system including two circuits, at least one of which has a variable voltage, two neon bulbs, a diftferent one of which is connected on one side with each of said circuits, a source of pulsating voltage, a resistance through which the source of pulsating voltage, is connected with the other sides of the neon bulbs, said source of pulsating voltage being correlated with a predetermined voltage which exists part of the time, and only part of the time, in the circuit having said variable voltage, the correlation being such as to produce a voltage differential, across the bulb that connects with said variable voltage circuit, which is above the firing voltage of the neon bulb during part, and only part, of each cycle of the pulsating voltage and below the extinguishing voltage of the neon bulb during another part of the cycle of the pulsating voltage, means supplying a voltage to the connection of the other neon bulb to the other of said two circuits at a voltage which is correlated with the voltage variations in the variable voltage circuit to fire said other neon bulb when the voltage in the variable voltage circuit decreases to extinguish the neon bulb that is connected on one side with said variable voltage circuit.

2. The electric system described in claim 1 characterized by a substantially constant direct current voltage power supply source connected with the circuit having the variable voltage, and the pulsating voltage power source for each neon bulb being a pulsating direct current source.

3. The electric system described in claim 1 characterized by the circuit having the variable voltage being a flip-flop multi-vibrator circuit, and the source of pulsating voltage and resistor for the neon bulbs being common to both bulbs, and a conductor joining terminals of both bulbs and to which the resistor is connected between the neon bulbs.

4. The electric circuit described in claim 3 characterized by the multi-vibrator circuit having two transistors, a conductor connecting each of the transistors with its source of power, a resistor forming a part of said conductor and located between the power source for the transistor and the connection of that transistors circuit with one of the neon bulbs, other conductors connecting the collector side of each transistor with the base of the other transistor, a resistor forming part of each of said other conductors, and signal pulse connections joined to said other conductors.

5. The electric circuit described in claim 3 characterized by the source of pulsating voltage being a direct current generator having a frequency cycle shorter than the on or off period of the flip-flop multi-vibrator circuit.

6. The method of controlling the operation of two neon bulb indicators for indicating the condition of a bi-stable system containing two circuits, including a circuit which contains a transistor and which has a voltage that varies with the condition of the transistor, and a second circuit, the first of the neon bulbs being connected on one side with the first circuit and the second of the neon bulbs being connected on one side with the second circuit, a common power source to which the other side of each of the neon bulbs is connected, and resistance in series with the common power source and the neon bulbs, which method comprises supplying power for the neon bulbs at higher voltage than that supplied to the transistor and lower than that required to maintain the bulbs lighted, supplying other power for the neon bulbs, and pulsing the other power supplied to one of the neon bulbs when the transistor is conducting, between a voltage in excess of the bulb firing voltage and a voltage less than that required to maintain the bulb lighted and with a frequency having a cycle shorter than the cycle of operation of the transistor, and at the same time impressing on the other neon bulb a voltage less than the voltage required to maintain the bulb lighted, and reversing the correlation of voltages on the neon bulbs when the transistor is not conducting.

7. The method described in claim 6 characterized by the system including two transistors in a fiip-fiop multivibrator circuit and the current supplied to the neon bulbs being pulsed at a frequency having 'a cycle substantially shorter than the on or ofi period of the multi-vibrator circuit.

8. The method described in claim 6 characterized by pulsing the power supply to the neon bulbs at a frequency that gives each neon bulb apparently continuous illumination.

9. An electric circuit including two transistors con nected for conducting alternately in accordance with signal pulses supplied to the circuit, means for connecting each of the transistors with a source of power, separate neon bulbs connected in the circuit in position to be grounded through the respective transistors, and a source of pulsating voltage for the neon bulbs different from the source of power for the transistors and of higher peak voltage than the voltage supplied to the transistors, the

5 6 source of the pulsating voltage being correlated with the 3,020,418 2/1962 Emile 307-291 X variable voltage in the transistor circuit to produce 21 volt- 3,168,728 2/ 1965 Porath 340 -252 age differential across the bulbs greater than the firing 3,344,308 9/1967 Atkinson 315-135 voltage of the bulbs under predetermined conditions in the respective transistor circuits, and a voltage difierential 5 JOHN W. HUCKERT, Primary Examiner that drops below the maintaining voltage of the neon bulbs during each cycle of the pulsating voltage. BRODER Assistant Examiner References Cited US. Cl. X.R.

UNITED STATES PATENTS 10 30729l; 3l5161; 340-252 2,840,728 6/1958 Haugh et al 307-29l X

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