• CIRCUIT FORMS DIVIDE BY 1.5 COUNTER
  Two inexpensive ICs divide a TTL clock signal by 1.5. By following the circuit with another flip/flop, you could also generate a divide by three function.

• DARKROOM CAMERA SHUTTER TIMER
  This circuit was designed to control a film exposure shutter for a darkroom. It has 8 time steps ranging from 0.35 seconds to 4 seconds. It is activated by a foot switch and draws power from an external 12 volt DC supply.

Darkroom camera shutter timer:  (diagram added 05/07)

DarkRoom Timer:  (electronic Circuit / Schematic added 10/04)

Day/Night/24 Hour Select Sensor:  (schematic added 8/03)

DDR2: The Next Generation Main Memory:  Pericom Semiconductor Application Note # 07)8 (app note added 02/05)

DDS using AD9835:  (schematic added 8/03)

Delay line has Wide duty cycle range:  06/27/02 EDN Design Ideas  /  (added 1/05)  Today's digital delay lines can process pulses no shorter than their delay times, and that restriction confines the devices to applications in which the duty cycle remains near 50%. A limited range of available delays (2 to 100 nsec per tap) further limits their use. Longer delay is available with one-shot multivibrators of standard digital-logic families, but those devices do not retain duty-c......

Deoderizer Fan Pushbutton Timer :  For use in a bathroom or car. I've seen similar circuits used in plastic pot-pourri containers.  (added 2/05)

Design Guidelines for PC100 Registered SDRAM Modules:  Pericom Semiconductor Application Note # 013 (app note added 02/05)

Design Guidelines for Registered DDR DIMM Module using PI74SSTV16857 Registers and PI6CV857 PLL Drivers:  Pericom Semiconductor Application Note # 037 (app note added 02/05)

Design Guides of PC133/100 Registered SDRAM Module:  Pericom Semiconductor App Note # 020 (app note added 02/05)

Design Low duty cycle timer circuits:  08/22/02 EDN Design Ideas  /  (added 1/05)  Designing astable circuits using the industry-standard 555 timer is a straightforward process when duty cycles are 50% or greater. However, you must overcome the many pitfalls of low-duty-cycle circuits to arrive at a desired result. Using only ideal components eases the design, but the components themselves are hard to obtain....

Designing and Characterizing TRL Fixture Calibration Standards For Device Modeling (11/20/01) :  Application Note California Eastern Laboratories Doc #954  (app note added 6/06)

Designing for Minimal Jitter When using Clock Buffers:  Pericom Semiconductor Application Note # 024 (app note added 02/05)

Differences of Pericom SuperClocks and Competitor Programmable Skew Clocks:  Pericom Semiconductor Application Note # 061 (app note added 02/05)

Digital Clock with Timer and Solar Panel Regulator:  This is a combination digital clock timer and solar panel charge controller used to maintain a deep cycle battery from a solar panel. The timer output is used to control a 12 volt load for a 32.... (added 05/07)

Digital Clock:  (electronic design added 10/06)

Digital countdown timer may never need battery replacement:  06/23/05 EDN Design Ideas  / (added 11/05)  Processor-based timer draws microamps.

Digital pedometer circuit:  (electronic circuit added 04/05)

Digital Stop Watch:  (electronic Circuit / Schematic added 10/04)

Digital Timer has Independent on/Off Periods:  03/28/96 EDN-Design Ideas / (added 03/03)  

Digital Timer Light Switch :  Typical circuit representative of those used in most light switch type digital timers. The timer module is normally a PIC or custom chip, and it syncs to the AC line so that a trigger pulse can be supplied at the right moment. (added 2/05)

Direct Digital Synthesizers in Clocking Applications Time Jitter in Direct Digital Synthesizer-Based Clocking Systems:  AN-823 Analog Devices Application Notes  (app note added 2/06) 

Divide by 1.5 counter (PFD):  (diagram added 05/07)

Divide by N using '161s:  (schematic added 8/03)

Doorbell with Counter:  (circuit added 7/02)

Dynamic Clock Provides for Zero Wait States:  03/27/97 EDN-Design Ideas / (added 3/03)  

Effects of Aperture Time and Jitter in a Sampled Data:  National Semiconductor Application Note   (app note added 6/06)

EMI Reduction Techniques:  Pericom Semiconductor Application Note # 011 (app note added 02/05)

Extend the timing capabilities of a PC:  01/10/02 EDN Design Ideas  /  (added 1/05)  Even when you use the internal timing registers and under DOS, a PC cannot easily measure time intervals with better time resolution than a millisecond. Measuring long intervals with even this precision is a waste of many CPU cycles. A microcontroller is well-suited for this task; you can easily integrate a PIC with a PC to extend the timing precision into the microsecond range for perio... ...