Showing posts with label contact. Show all posts
Showing posts with label contact. Show all posts
Tuesday, November 4, 2014
Non Contact Power Monitor
Here is a simple non-contact AC power monitor for home appliances and laboratory equipment that should remain continuously switched-on. A fuse failure or power breakdown in the equipment going unnoticed may cause irreparable loss. The monitor sounds an alarm on detecting power failure to the equipment. The circuit is built around CMOS IC CD4011 utilising only a few components. NAND gates N1 and N2 of the IC are wired as an oscillator that drives a piezobuzzer directly. Resistors R2 and R3 and capacitor C2 are the oscillator components. The amplifier comprising transistors T1 and T2 disables the oscillator when mains power is available. In the standby mode, the base of T1 picks up 50Hz mains hum during the positive half cycles of AC and T1 conducts.
Non-Contact Power Monitor Circuit diagram:
This provides base current to T2 and it also conducts, pulling the collector to ground potential. As the collectors of T1 and T2 are connected to pin 2 of NAND gate N1 of the oscillator, the oscillator gets disabled when the transistors conduct. Capacitor C1 prevents rise of the collector voltage of T2 again during the negative half cycles. When the power fails, the electrical field around the equipment’s wiring ceases and T1 and T2 turn off. Capacitor C1 starts charging via R1 and preset VR and when it gets sufficiently charged, the oscillator is enabled and the piezobuzzer produces a shrill tone. Resistor R1 protects T2 from short circuit if VR is adjusted to zero resistance.
The circuit can be easily assembled on a perforated/breadboard. Use a small plastic case to enclose the circuit and a telescopic antenna as aerial. A 9V battery can be used to power the circuit. Since the circuit draws only a few microamperes current in the standby mode, the battery will last several months. After assembling the circuit, take the aerial near the mains cable and adjust VR until the alarm stops to indicate the standby mode. The circuit can be placed on the equipment to be monitored close to the mains cable.
Saturday, September 13, 2014
Part 4 Contact info and web adresses of integrated circuits power audio amplifiers manufacturers
Mag- Magnatec (Semelab Subdivision)
Semelab Plc. Coventry Road, Lutterworth, UK. Phone: +44-1455-552505
http://www..semelab.co.uk
Max- Maxim Integrated Products
120 San Gabrial Sunnyvale, CA 94086, USA. Phone: +1-800-998-8800
http://www.maxim-ic.com
Mcp- Microchip Technology Inc.
2355 West Chandler Blvd. Chandler, AZ 85224-6199, USA. Phone: 480-792-7200
http://www.microchip.com
Mit- Mitsubishi Electric Co. Ltd. (ICs manufacture is handed to Renssas Ltd.)
2-3 Marunouchi, 2-chome J 100 Chiyoda-Ku, Tokyo, Japan. Phone: +81-3-3218-2863
http://www.mitsubishichips.com
Mot- Motorola Inc. (ICs manufacture is handed to ON Semiconductor)
6501 William Cannon Drive W Austin, TX 78735 USA. Phone: +1-512-891-2000
http://www.motorola.com
Mps- Monolithic Power Systems
6409 Guadalupe Mines Road, San Jose, CA 95120, USA. Phone: 408-826-0600
http://www.monolithicpower.com
Mts- Mitsumi Electric Co. Ltd.
8-8-2, Kokuryo-cho, Chofu-chi, Tokyo 182-8557, Japan. Phone: (03)3489-5333
http://www.mitsumi.co.jp
Msk- M.S.Kennedy Corp.
4707 Dey Road Liverpool, N.Y. 13088 USA . Phone (315) 701-6751
www.mskennedy.com
Mul- Mullard LTD (Is not a current ICs manufacturer)
New Road Mitcham, Surrey England CR4 4XY. Telex: 264341
NEC Electronics Inc. (Nippon Electrical Company)
NEC Building 7-1, Shiba 5-chome, Minato-ku Tokyo, Japan. Phone: +81-3-3454-1111
http://www.ic.nec.co.jp
NJR- New Japan Radio Co., Ltd.
Arvco Tower 17F, 1-8-1, Shimomeguro, Meguro-ku, Tokyo 153, Japan.
Phone: +81-3-5434-8335
http://www.njr.com
Npc- Nippon Precision Circuits Inc.
4-3, Fukuzumi 2-chome, Koto-ku, Tokyo 135-8430, Japan. Phone:+81-3-3642-6661
http://www.npc.co.jp/453
NSC- National Semiconductor Corp.
North America PO Box 7643 Mount Prospect, IL 60056-7643, USA.
Phone: +1-800-628-7364, ext 305
http://www.national.com
NTE Electronics Inc.
44 Farrand Street, Bloomfield, NJ 07003, USA. Phone: 800-631-1250
http://www.nteinc.com
Nxp- NXP Semiconductors
PO Box 80073, 5600 KA Eindhoven, Netherlands. Phone: +31 40 27 45678
http://www.nxp.com
Oki Semiconductor Inc.
785 N Mary Avenue Sunnyvale, CA 94086, USA .Phone: +1-408-720-1900
http://www.okisemi.com
Omn- Omnirel (Acquired by International Rectifier)
205 Crawford Street, Leominster, MA 01453 USA. Phone: (508) 534-5776
http://www.omnirel.com
Ons- ON Semiconductor (Motorola semiconductors subdivision)
Japan Customer Focus Center 4321 NishiGotanda, Shinagawaku, Tokyo, Japan
Phone: 81357402745
http://onsemi.com
Pan- Panasonic Electronics Corp.
1 Kotari-Yakemashi, Nagaokakyo, Kyoto 617, Japan. Phone: 075/921-8151
http://www.mec.panasonic.co.jp
Pch- PointChips Co. Ltd.
4FL., Dabong Tower Bldg. 890-12, Daechi-Dong, Kangnam-Gu, Seoul 135-280, Korea
Phone: 82-2-508-2443
http://www.pointchips.com
Phi- Philips GmbH (ICs manufacture is handed to NXP Semconductor)
Hammerbrookstrasszlige 69 D-20097 Hamburg, Germany. Phone: +49-40-23536-0
http://www.philips.com
Pjn- Promax-Johnton
(There is no accesible padding information)
http://www.p-johnton.com
Pls- GEC Plessey Semiconductor
(Is not a current ICs manufacturer)
Pnr- Pioneer Not the manufacturer of ICs
Will use custom IC with Pioneer type marking
Ptc- Princeton Technology Corp.
2F, No. 233-1, Baociao Road, Sindian City, Taipei 23145, Taiwan, R.O.C.
Phone: 886-2-66296288
http://www.princeton.com.tw
Rca- RCA Corporation (Is not a current ICs manufacturer)
Route 202, Sommerville, NJ 08876, USA. Phone: 201/685-6423
http://www.rca.com
Ren- Renessas Ltd.
Nippon Bldg., 2-6-2, Ohte-machi, Chiyoda-ku, Tokyo 100-0004, Japan,
Phone: 852-2424-9127
http://www.renesas.com
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