• Two Pushbutton Motor Controller
  Two small pushbutton switches, a few diodes and two relays form a method to control on/off power to a brush motor as well as the motor direction.  The circuit was originally designed for a motorized lifting platform.

Watchdog Circuit Protects Against Loss of Battery Charger's Control Signals - 07/21/05, EDN-Design Ideas:  Hardware circuit keeps software-based charging within limits.....(design idea added 10/05)

Watchdog Circuit uses AC Triggering - 08/16/01, EDN-Design Ideas:  A dc-triggered reset of a watchdog circuit is prone to failure. If the watchdog program hangs up, then the reset signal becomes activated continuously, and the microprocessor has no way to escape the situation. We found that a simple solution uses an ac trigger to reset the watchdog circuit (Figure 1).....(design idea added 1/05)

Watchdog Circuit uses Leftover Gates - 08/01/96, EDN-Design Ideas:  (design idea added 3/03)

Watch-Dog for Telephones - Most of the telephone security devices available in market are simple but quite expensive. These devices provide blinking or beeping type line-tap/misuse indications. Quite often they do not offer guaranteed protection against unauthor-ised operation. A very simple and uni- que circuit of a telephone watch-dog to safeguard subscriber telephone lines against any fraud is described here. This little circuit keeps continuous watch over the telephone lines and sounds an alarm in case of any misuse. In addition it transmits a loud tone through the telephone lines to prevent further misuse. ….(electronic schematic added 11/08)

Watchdog reset catcher aids embedded system debugging  - 11/19/98, EDN-Design Ideas:  (design idea added 6/06)

Watchdog Time Out is Independent of Reset - 09/01/95, EDN-Design Ideas:  (design idea added 3/03)

Watchdog Timer Allows Entry to Test Mode - 07/19/01, EDN-Design Ideas:    Manuals for microprocessor-based devices often include instructions for entering a "secret mode" in which you can test or reset the device. These instructions typically ask you to depress and hold one or two switches for a minimum time interval. You can adopt several measures.....(design idea added 1/05)

Watchdog Timer Assumes Varied Roles - 02/01/01, EDN-Design Ideas:.....(design idea added 05/03)

Watchdog Timer Reboots PC's - 06/05/97, EDN-Design Ideas:  (design idea added 3/03)

Water-Level Controller - (electronic Circuit / Schematic added 10/04)

Welch Scientific Model 2153c Stroboscope - a schematic for a typical line operated variable rate stroboscope used for the visualization of moving parts as well as rotation speed or frequency determination of rotating or vibrating machinery (added 4/02)

Welding High Power - (application / block diagram added 6/07)

White LED Head Lamp - A white LED head lamp which can operate with only two AA batteries. The LEDs are driven in constant current, so that the brightness is maintained until end of battery life.  (added 6/06)

Wideband Agc Amplifier as a Differential Amplifier - National Semiconductor Application Note 10-Apr-2000 (app note added 4/02)

Wideband AGC has 60 DB Dynamic Input Range - 10/10/96, EDN-Design Ideas:     /.....(design idea added 5/02)

Wiper Speed Control - (circuit / schematic design added 6/06)

Wireless RF PWM Dual Motor Controller - (electronic circuit added 4/05)

ZXBM200x Series of Variable Speed 2-Phase Fan Motor Controller - Zetec Semiconductors  Applications Notes This applications document is intended to aid users in their development of the controller electronics for fan and blower motors using the ZXBM200x series of variable speed, 2-phase, DC brushless motor controllers.   (app note added 6/06)