Communications: electrical – Condition responsive indicating system – Specific condition
Patent
1993-11-04
1995-08-29
Swarthout, Brent
Communications: electrical
Condition responsive indicating system
Specific condition
340634, G08B 2100
Patent
active
054464501
ABSTRACT:
A tower light controller comprises logic circuitry that easily connects with equipment used in the production of semiconductor wafers. The tower light controller uses the existing signals in the production equipment, namely a process signal, an alarm signal, left and right cassette present signals, and left and right atmosphere signals, to appropriately drive a light tower comprised of a yellow lamp, a red lamp, and a green lamp. The logic circuitry turns on the green lamp when a product is being run. A yellow lamp is continuously driven when the equipment has wafers that are ready to be unloaded and the yellow lamp is flashed when the equipment is ready to be loaded with wafers. The red lamp is flashed during alarm conditions and is driven continuously when the equipment is placed in a repair or in a preventative maintenance mode. The logic circuitry also comprises an oscillator formed by a series connection of three inverters. A pair of resistors are connected in series with each other and across the first and third inverters. A capacitor has one terminal connected between the second and the third inverters and the other terminal connected between the two resistors. The circuit additionally comprises a pair of LEDs, reverse biased with respect to each other, connected across the second inverter. With the addition of the two LEDs, the frequency of the oscillating signal may be lowered past the typical floor of 4 to 7 Hz down to about 0.25 Hz.
REFERENCES:
patent: 4682927 (1987-07-01), Southworth et al.
patent: 4828224 (1989-05-01), Crabb et al.
patent: 5092728 (1992-03-01), Crabb et al.
patent: 5153841 (1992-10-01), Goff et al.
patent: 5166884 (1992-11-01), Maney et al.
patent: 5256204 (1992-10-01), Wu
Kananen Ronald P.
Mannava Ashok
Sony Electronics Inc.
Swarthout Brent
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