Wednesday, August 20, 2014

1.5 V Inductance Meter Circuit

Here a simplest yet quite accurate inductance meter is presented, which can be built within few minutes. Furthermore, the circuit can be powered-up with a single 1.5V cell. However, a frequency meter would be required to work-out the inductance.

Lithium Polymer Battery Charger Circuit

The post explains a simple lithium polymer battery with over charge cut off feature. The idea was requested by Mr. Arun Prashan.

Sunday, August 17, 2014

Cellphone Controlled Car Starter Circuit

The post presents a simple cellphone triggered remote control circuit that can be applied as a cellphone operated remote car starter. The unit would cost less than $20 to build.

Saturday, August 16, 2014

3.7 V Class-D Speaker Amplifier for Differential Analog Input

A class D amplifier is basically a category of amplifier in which the power devices (mosfets and BJTs) are operated like switches.

Making a Small Induction Cookware

The post explains a simple small induction cookware heater circuit or an induction kadai circuit. The design is a low tech, low power design, and may not be on par with the conventional units. The circuit was requested by Mr. Dipesh Gupta

Sunday, August 10, 2014

Switching OFF Lights in a Periodic Sequence

 The post explains a circuit that will switch off a group of lamps in sequence with a predetermined delay rate, as set by the user through a built in pot. The ideas was requested by Mr. Azam Jamal

Monday, August 4, 2014

Spy Circuits - FM Bug Transmitters

All the spy circuits presented below are significantly powerful, hard to trace in their hidden positions, and equipped for grasping even the weakest of whispers in the vicinity. Moreover the designs are capable of transmitting the picked information upto radial distances exceeding 2 kms.

Sunday, August 3, 2014

LM317 as a Variable Voltage Regulator and Variable Current Regulator

The post shows how the versatile IC LM317/338/396 may be used as a variable voltage regulator and also as a variable current regulator through simple configurations.

Making a Regulated 9V Battery Eliminator Circuit

The post presents a regulated 9V battery eliminator circuit which was built and investigated by Mr. Steven Chiverton, an avid reader of this blog and an experienced electronic hobbyist. Let's learn more from him.

6V, 12V Battery Charger Circuit for Positive Earth Cars

 The post presents an enhanced battery charger circuit idea which could be used for upgrading 6V positive earth cars, facilitating an external 12V battery to be used in them along with the existing 6V battery with a common positive earth body. The idea was requested by Mr. Joe Ceretti.
Readers are advised to proceed with the construction of the presented circuits only after understanding the concepts from the core. Not adhering to this can lead to failures and frustrations.