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Versatile Special Function Timer - This automatic timer has a wide range of applications whereby a timing cycle is initiated in response to a trigger signal. There are quite a few uses for it in a car or you could use it on a model railway layout, in a home security system or whatever.__ SiliconChip Versatile Timer IC - an 8-pin pic generating hourly/daily pulses, saves lots of circuitry - example circuits also __ Contact P. Townshend - EduTek Ltd
VersaTimer/Switch with Self-Latching Relay - Use it as a micropower switch, programmable timer and/or 12V battery protector__ SiliconChip
VFD (vacuum flourescent display) clock - This is my fifth retro display clock (others: 1, 2, 3, 4) , but the first based on a vacuum fluorescent display. Let's get right down to it. __ Designed by © 2007 Riad S. Wahby
Video Clock Superimposer using PIC16C711 - As a followup to my VCR Pong project, here is a gadget that is actually useful in the Real World! it superimposes the time of day, in "HH MM SS" format, in the bottom right-hand corner of an existing video signal. My friend Scott uses it with his home security system__
Visitors Counter - Presented here is a simple counter that counts the number of visitors entering or exiting an auditorium or any other place where you have installed this circuit at the gates. On...__ Electronics Projects for You
Voltage Controlled Oscillator with 16:1 Frequency Range - The LTC6990 is a precision silicon oscillator with a programmable frequency range of 488Hz to 2MHz. it can be used as a fixed-frequency or voltage-controlled oscillator (VCO). The LTC6990 is part of the TimerBlox family of versatile silicon timing devices. A single resistor, RSET, programs the LTC6990’s internal master oscillator__ Linear Technology/Analog Devices App Note, Jun 16th 2010
Voltage Controlled Switch using 555 - in this circuit the 555 timer is used in a novel way, as a voltage controlled switch. __ Designed by Miroslav Adzic
Voltage Doubler - A voltage higher than the supply can be created by a "Charge-Pump" circuit created with a 555, diodes and capacitors as shown in the following circuit. The output will deliver about 50mA. __ 555-Timer
Voltage Inverter using 555 Timer - Simple and inexpensive circuit can produce a dual (positive and negative) voltage from a single supply input, extremely useful for powering OpAmp and other circuits that require a dual voltage from a single battery. __ Designed by Aaron Cake
Wailing Siren - By pressing the button, the wailing sound increases. Releasing the button decreases the wailing. The circuit automatically turns off after about 30 seconds. __ 555-Timer
Watch Man Watcher - Here is a circuit that can be used in offices, stores, warehouses, etc during night to check whether the watchman of your establishment is on duty. For operation, it uses an...__ Electronics Projects for You
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...__ Electronics Projects for You
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. __
Watchdog protects against loss of battery charger's control signals - 21-Jul-05 EDN Design Ideas: Hardware circuit keeps software-based charging within limits Design by Andy Fewster, Maxim Integrated Products Inc, Hampshire, UK
Watchdog reset catcher aids embedded system Debugging - 11/19/98 EDN Design Ideas: NOTE: Multiple circuits included. Scroll to find this one. A simple "junk-box" circuit uses a 4013 CMOS
flip-flop and a handful of passive components to determine whether random resets are the result of a blown stack or the result of the watchdog-reset circuit tripping (Figure 1). You can also use this circuit to "grab" and hold Design by Scott Newell, PCSI, Fort Smith, AR
Watchdog Time-Out Is Independent Of Reset - 09/01/95 EDN Design Ideas: Many embedded systems use µP supervisors with on-chip watchdog timers. Some supervisors, such as the MAX691, allow you to select different watchdog and reset time-out periods, depending on how you connect pin 7 (Osc in] and pin 8 (Osc Sel]. Table 1 in the MAX691 data sheet indicates the available watchdog and reset time-out choices. However, when you implement Design by Larry Buyan, Criticare Systems Inc, Waukesha, WI
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 Design by Greg Sutterlin and Larry Barnes, Maxim Integrated Products, Sunnyvale, CA, and Craig Gestler, Mining Safety Appliances Co, Mars, PA
Watchdog timer assumes varied roles - 02/01/01 EDN Design Ideas: The MAX6369-74 series of pin-selectable watchdog timers are designed to superviseµP activity and indicate when a system is working improperly. During normal operation, aµP should repeatedly toggle the WDI (watchdog input) before the selected watchdog-time-out period elapses to indicate that the system is properly executing code. Design by Terry Millward, Maxim Integrated Products, Lambourn Hungerford, UK
Watchdog Timer for Robust Embedded Systems - n a complex embedded system, a small bug may crash the whole system, or worse, put it into a dangerous operating mode. Bugs are not the only problem. A perfectly-designed-and-tested device on which a perfect code executes can still fail. A watchdog timer (WDT) is a safety mechanism that brings the system back to life when it crashes. For this reason, it must be well-designed and implemented for robust embedded system development.__ Pratyush Gehlot
Watchdog Timer Reboots PC's - 06/05/97 EDN Design Ideas: When you use a PC to control a process or collect data, it's often desirable to have a watchdog timer reboot the computer if it runs astray. The circuit in Figure 1 uses a PIC 16C84. Design by Charles Hamilton, Burr-Brown Corp, Tucson, AZ
Watchdog Timer set for 36 Hrs - A watchdog timer is often used in computer systems to detect when a computer is hung up and is no longer running properly. if it does become locked up and is not able to supply a reset pulse to the circuit within a defined time frame the timer times out a . . . Hobby Circuit designed by David Johnson P.E.-April, 2010
Watchdog 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 by Shyam Tiwari, Sensors Technology Private Ltd, Gwalior, India
Watchdog uses Leftover Gates - 08/01/96 EDN Design Ideas: The reset and µP-controlled watchdog circuit in Figure 1 a makes good use of some unused inverter gates in IC 1. The design is extremely simple. The circuit is a continuously running oscillator with programmable high- and low-level pulse widths that have additional intervention-control input from the µP. Because the circuit is a continuous running oscillator, the circuit generates Design by Shyam Sunder Tiwari, IGCAR, Kalpakkam, India
Weekly Reminder - This circuit reminds you of all the important tasks that are due on a specific day every week. So be it returning your library book, switching on your favourite TV programme, ...__ Electronics Projects for You
Weston Voltmeter Clock - This was the first clock I built, but I'vesince built a couple others, a single-digit NiXiE and a CRT clock, so the whole count-60-cycles seems like old hat at this point. The PIC sits there interrupting on RA4/T0CKI and dutifully keeping count of those oh-so-accurate (at least, over long periods of time) cycles coming out of the wall. __ Designed by © 2007 Riad S. Wahby
Wide Frequency Range 555 VCO - The 555 frequency can be varied via adjusting the voltage at pin 5. However, the range and linearity of frequency adjustment is very limited. This is a way to greatly improve performance using the inverted 555 timer circuit that was previously posted.555 VCO Schematic Current source Q2 is connected in the common base __ Designed by Jim Keith
Wide-swing Variable Crystal Oscillator - Timing and oscillator circuit diagrams / circuit schematics __ Designed by Peter Parker VK3YE
Wien Bridge Oscillator with SPICE simulation - Timing and oscillator circuit diagrams / circuit schematics__
Windshield Wiper Delay - The intermittent wiper circuit shown above causes the auto's windshield wipers to wipe once every several seconds instead of constantly wiping. The circuit may be added to older cars to provide the intermittent function or it __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Xtimer V1.0 - Easy build 4-channel timer, suitable for energy saving, simple hardware and nice firmware with c coding. Automatic power down mode, simple settings, optional buzzer for sound alarm. __ Designed by Wichit Sirichote |
