Scheme Saves String Light Situation:  12/16/04 EDN on Components (added 1/05) As you enter the holiday season with strings of ac-line-powered lights hanging everywhere, do you ever wonder how bulb vendors overcame the frustrating problem of having an entire string go dark when just one of th

Sequencing Neons (Ne 51/Ne 2):  (electronic circuit added 7/03)

Sequential Brake/Turn Lights:  [b:13d93a01a2]Bar-mode LED-cluster sequencer Can drive up to 16 clusters[/b:13d93a01a2] [b:13d93a01a2]Comments:[/b:13d93a01a2] This circuit, designed on request, allows up to 16 LED clusters.... (added 2/07)

Sequential LED Flasher:  for10 LEDs (added 4/02)

Simple Flashing Light Circuit 1:  (electronic circuit added 4/05)

Simple Flashing Light Circuit 2:  (electronic circuit added 4/05)

Simple Flashing Light Circuit 3B:  (electronic circuit added 4/05)

Simple Scheme Saves String Light Situation:  12/16/04 EDN on Components (added 1/05) As you enter the holiday season with strings of ac-line-powered lights hanging everywhere, do you ever wonder how bulb vendors overcame the frustrating problem of having an entire string go dark when just one of th

Simple Tester Checks Christmas Tree Lights:  12/16/04 EDN on Components (added 1/05) 1Why is it that you always test 48 bulbs before you find the bad one in a 50-light string? This simple circuit allows you to divide and conquer, greatly reducing the time it takes to find the bad bulb.

Simple Timer Exploits Opamp Bias Current:  07)/21/94 EDN-Design Ideas / (added 5/03) The simple, low-cost analog timer in Fig 1 exploits the parasitic input-bias current of op-amp IC1. The timer achieves long time delays even though it uses only low-value, inexpensive ceramic chip capacitors. After all, because the input-bias current is the minimum current flow into an op amp, this method produces the longest time delays possible from a given capacitor and op amp....  

Small Transformer Drives Large El Panel:  03/01/96 EDN-Design Ideas / (added 03/03)

Smart Phone Light:  (electronic circuit added 10/05)

Smart Ringing Phone Light:  The circuit shown here is used to switch on a lamp when the Telephone rings, if the ambient light is insufficient. (added 4/02)

Solar Powered Reading Lamp:  (electronic circuit added 10/05)

Special Effects from a Six Pack:  Four channel Sequencer to Analog Dimmers and idea how to couple relay to the circuit (added 4/02)

Strange LED Sequencer:  This bizzare but simple PWM circuit fades from LED to LED. This deceptively simple sequencer actually pulse width modulates the LEDs as it fades from one LED to the next. Bulbs will last much longer when driven in this gentle manner; add FETs or transistors to the outputs if you wish to drive bulbs. You can reconfigure the capacitors from a delta configuration to a star configuration, or you can remove one of them entirely and the circuit will still function. Use high efficiency red LEDs for best results. This circuit was inspired by the BEAM sequencer circuits on the web. I simply reversed the roles of the resistors-capacitors and 'floated' the capacitors to create this monstrosity which incidentally chirps out RF interference as it hobbles along. (added 2/05)

Strobe Controller:  Simple controller for professional stroboscopes, adjust the flash rate in1.15 Hz range (added 6/03)

Strobe Light #1:  (electronic circuit added 7/03)

Strobe Light 12 Volt Coil Powered:  (electronic circuit added 11/06)

Switching Regulator Controls Ccft:  02/16/95 EDN-Design Ideas / (added 3/03) You can control the current in a cold-cathode fluorescent tube (CCFT) and, hence, its brightness with a switching-regulator IC

Switching Regulator Turns into Light Source:  07)/17/97 EDN-Design Ideas / (added 3/03)   -Simple external feedback circuit transforms a switching regulator into a constant-intensity light source