CIRCUIT || A HIERARCHICAL PRIORITY ENCODER

Anormal priority encoder encodes only the highest-order data line. But in many situations, not only the highest but the second-highest priority information is also needed. The circuit presented here encodes both the highest-priority information as well as the second-highest priority information of an 8-line incoming data. The circuit uses the standard octal priority encoder 74148 that is an 8-line-to-3-line (4-2-1) binary encoder with active-‘low’ data inputs and outputs.

Download Full Circuit: http://adf.ly/Vajh8

Circuit || 9 LINE TELEPHONE SHARER

This circuit is able to handle nine independent telephones (using a single telephone line pair) located at nine different locations, say, up to a distance of 100m from each other, for receiving and making outgoing calls, while maintaining conversation secrecy.

Download Full Circuit: http://adf.ly/Vb89R

CIRCUIT || 15- STEP DIGITAL POWER SUPPLY

Here is a simple circuit to obtain variable DC voltage from 1.25V to 15.19V in reasonably small steps as shown in the table. The input voltage may lie anywhere between 20V down by closing switch S2.

Download Full Circuit: http://adf.ly/Vb8qJ

CIRCUIT || STEREO PREAMPLIFIER

This easy-to-build hi-fi preamp features high-performance audio op amps for ultralow noise and distortion. Its modular design incorporates five switched RCA phono inputs and support for a headphone amplifier.

Download Full Circuit: http://adf.ly/VpL9W

CIRCUIT || 40-METRE DIRECT CONVERSION RECEIVER

Using the circuit of direct-conversion receiver described here, one can listen to amateur radio QSO signals in CW as well as in SSB mode in the 40-metre band.

Download Full Circuit: http://adf.ly/VbJDe

ACCURATE ELECTRONIC STOP-WATCH

Here is a simple circuit which can be used as an accurate stop-watch to count up to 100 seconds with a resolution of 0.01 second or up to 1000 seconds with a resolution of 0.1 second. This stop-watch can be used for sports and similar other activities.

Download Full Circuit:http://adf.ly/VoZry