Whisker for Robots
Whiskers for robots are simple switch-type sensors that work like an animal’s whiskers detecting nearby objects in the environment. When disturbed, the sensor sends...
TRANSISTORISED LOGIC PROBE FOR TTL
A logic probe is a handheld pen-like probe used for analysing and troubleshooting the logical states '0' or '1' of a digital circuit. While...
INVERTER FOR SOLDERING IRON
Here is a simple but inexpensive inverter for using a small soldering iron (25W, 35W, etc) in the absence of mains supply. It uses...
LED And Luminaire Testing Can’t Be Taken Lightly
Standards and tests are essential to evaluate the quality and longevity of LEDs and luminaires. So test and measurement solutions have to keep pace...
Design And Test Challenges Of Frequency-Hopping Radios
The erratic behaviour of frequency-hopped signals makes them difficult to capture, verify and measure. Hence more effective tools and processes are required to design...
Looking Into The Brain For Lie Detection
Though the reliability of brain scanning for lie detection is still under question, these tests are fast becoming popular with the crime investigating teams....
MULTI-SWITCH DOORBELL WITH INDICATORS
Here’s the circuit of a multi-switch input musical doorbell (shown in Fig.1). The circuit is built around the popular and less expensive quad D-latch...
KNOCK ALARM
This circuit (Fig. 1), used in conjunction with a thin piezoelectric plate,senses the vibration generated on knocking a surface (such as a door or...
Night Lamps
Here are two night lamp circuits using LEDs. One could be used as a night-vision clock and the other as a TV lamp. Both...
Musical Water Shower
Won’t it be nice to have music playing in the background all the while when you take a shower? This simple circuit does the...
