DE1080688B - Ignition control of a flash unit - Google Patents

Description

There are many applications for flash units in today's computing systems, especially in systems that which include a cathode ray tube output unit. The output information of the computer systems are visualized on the screen of a cathode ray tube and then photographically recorded in a movie. Often the requirement arises here on the film at certain points record a frame or outline in which the information from the computer will be entered should. The outline of the page is generally recorded with the aid of a flash device located below the Control of a signal from the computer system is ignited. If the device for any Reason, z. B. due to aging or overheating of the flashlight discharge lamp, not ignited by the signal was, the computing system was blocked immediately.

A flashlight discharge lamp can fail 1 in 100,000 flashes, but that doesn't necessarily mean that the lamp needs to be replaced or that it cannot perform another 100,000 flashes. It it would therefore be preferable not to lock the computer system if the flash lamp fails, but instead try to ignite the lamp a second or third time, as the case may be.

The object of the invention is therefore to provide a control circuit for igniting a flash unit to create, through which the ignition is automatically repeated if the lamp fails.

The invention relates to an arrangement for controlling the ignition of a flash discharge lamp by stages of a voltage pulse consists in that a pulse generator (Tl, Rl, 12, 14, Ria, 19, 21 to 23) for the repeated generation of ignition pulses through the voltage stage (: -30 , +10) is switched on and the pulse is triggered by a voltage level caused by the discharge current of the flash lamp (L). (+ 10, -30) in the opposite direction is switched off. By discharging one of a lightning discharge

electrode associated capacitor during ignition

The flash lamp generates an output signal that controls the shutdown of the pulse generator. Of the - Pulse generator consists of an oscillator with a downstream pulse transformer, the is operated by a switch controlled by the oscillator via a relay. The oscillator in turn contains an input tube controlled by the voltage stages, the anode circuit of which contains the relay and another switch operated when the input tube is turned on. This switch discharges you Oscillator capacitor, which extinguishes a glow path and thus blocks the input tube will. The control of a pulse generator up to the ignition control of a flash unit

Applicant:

IBM Germany
International office machines

Gesellschaft mbH,
Sindelfingen (Württ), Tübinger Alle 49

Claimed priority:
V. St. v. America 9 September 1957

Edwin Joseph Srmua, Apalachin, NY,
and Richard Joseph Carnevale, Endicott, NY

(V. St. A.),
have been named as inventors

Igniting a gas discharge lamp is known per se, as is the use of relays to switch the Ignition circuit and for deriving a control pulse from the discharge current of gas discharge lamps.

The invention is now illustrated by an exemplary embodiment explained in more detail with reference to the drawing.

A positive input signal (e.g. -30 to +10 volts) is applied to input terminal 10 by a computer or other signal source. The potential of the control grid 11 is increased and the tube T1 is conductive. A relay Rl is connected to the output of the tube Tl- , which closes the contacts Ria and RIb when it is excited. In parallel with the contact Rl α , a capacitor 12 is placed between earth and a 300 volt voltage in such a way that it is normally charged to 300 volts and discharges via the primary winding 13 of a pulse transformer 14 when the contact Ria is closed. This induces a high voltage in the secondary winding 15, which causes the flashlight discharge lamp L to ignite. A capacitor 16 assigned to a lamp electrode between earth and an 800 volt voltage is now discharged via the flash lamp and causes a very strong flash. With the current flowing over the discharge path, a resistor 17 connected in series with the lamp generates a detection signal which is sent back via the terminal 18 to the signal source

009 507/187

to indicate that the lamp has flashed and also causes that to be applied to terminal 10 Input signal drops back to - 30 volts.

Together with the contact Ria , the contact RIb also closes, and as a result a capacitor 19 parallel to the contact RIb , which is also between earth and the 300 volt voltage, is discharged and lowers the potential at point 20. Between point 20 and the control grid 21 of a cathode amplifier 22 normally conductive glow lamps 23 are connected, which are extinguished when the capacitor 19 is discharged and thereby lower the potential at the control grid 21. The output of the cathode amplifier is connected to the screen grid 24 of the tube T1. By lowering the potential at the grid 21, the output of the cathode amplifier is reduced so that the screen grid 24 blocks the tube T1. This switches off relay R 1 and opens contacts Ria and RIb.

The value of the capacitor 19 is selected in relation to the value of the charging resistor so that it takes about 100 milliseconds until the capacitor has recharged to 300 volts after the contact RIb has opened. This increases the output of the cathode amplifier 22 again, so that the potential at the screen grid 24 prepares the tube T1 to become conductive. During this time, the capacitors 12 and 16 also recharge in order to make the circuit ready to respond. The delay of 100 milliseconds is intended to limit the number of flashes per second to ten so that the output of the flash lamp is not exceeded.

If the lamp does not flash, as is the case, for. B. can occur when the lamp ages or heats up, then no detection signal is available at terminal 18 for transmission back to the computer system. However, this does not reduce the signal at terminal 10, but remains at +10 volts. After the delay of 100 milliseconds, relay R1 is energized again and the ignition process is repeated.

In the exemplary embodiment of the invention, the pulse transformer is a relay circuit instead of the conventional thyratron discharge. The relay leaves the pulse transformer vibrate with its natural frequency. So several impulses are emitted and a larger one Ignition reliability of the flashlight lamps ensured.

Claims (7)

Patent claims: Pulse generator (Tl, Rl, 12, 14, Ria, 19, 21 to 23) for repeated generation of ignition pulses by the voltage level (- 30, + 10) switched on and by a voltage level (+10 , - 30) in the opposite direction is switched off. 2. Arrangement according to claim 1, characterized in that when the flash discharge lamp (L) is ignited, a capacitor (16) assigned to a flash discharge electrode is discharged and thus an output signal (18) is generated which shows the voltage level in the opposite direction for switching off the pulse generator (Tl , Rl, 12, 14, Ria, 19, 21 to 23). 3. Arrangement according to claims 1 and 2, characterized in that the pulse generator consists of an oscillator (Tl, Rl, 19, 21 to 23) with a pulse transformer (14) which is driven by one of the oscillator (Tl, Rl, 19, 21 to 23) controlled switch (Ria) is operated. 4. Arrangement according to claim 3, characterized in that the oscillator (Tl, Rl, 19, 21 to 23) consists of an input tube (Tl) controlled by the voltage stages, the anode circuit of which actuates a further controlled switch (R 1 b) , which, when the input tube (Tl) becomes conductive, discharges an oscillator capacitor (19), the charging time constant of which is 0.1 second, and thus makes a glow discharge path (23) between this capacitor (19) and the grid (21) of a cathode amplifier stage non-conductive, making it non-conductive Cathode amplifier stage, the output of which is connected to the screen grid (24) of the input tube (Tl), and the input tube (Tl) is blocked. 5. Arrangement according to claims 3 and 4, characterized in that the two controlled switches (R 1 α and RIb) via a relay winding (Rl) in the anode circuit of the input tube (Tl) are operated. 6. Arrangement according to claims 1 to 5, characterized in that the charging time constants another capacitor connected in parallel to the pulse transformer (14) in the operating state (12) and the capacitor assigned to one electrode of the flash discharge lamp (L) (16) is also 0.1 second. 7. Arrangement according to claims 1 to 6, characterized by the use in calculating machine output units with cathode ray tubes. 1. Arrangement for controlling the ignition of a document under consideration: Flash discharge lamp through steps of a chip 55 German Patent Nos. 947 993, 1 002 465, voltage pulse, characterized in that 'a 864 805. 1 sheet of drawings • ® 009 507/1 & 7 *.