Noise meter , Handy Tester and Straight Timer

Noise meter
Clamor contamination is tends to numerous non-transferable sicknesses and. Safe level of commotion is considered up to 30 dB. Here is a fascinating circuit by dream lover innovation, "Clamor Meter" used to quantify the level of clamor arraigning by LED and what's more it give cautioning when commotion crosses the sheltered level of 30 dB by beeping sound. 


Circuit depiction of Noise meter
The whole circuit of clamor meter has been outlined and created utilizing sound power sensor furthermore, show unit. Here condenser amplifier is utilized as sensor of commotion meter with operational speaker (IC2) and relating latent segments. The reversing and non-rearranging info is given to operational speaker IC (IC2) from stick 2 and stick 3 separately. Where yield from stick 6 of IC2 is associated with the transforming contribution for negative criticism through resistor R5. The controlling sound air conditioning signal from potentiometer VR1 is initially corrected by diode (D1 and D2) and keeps up it at the yield level of IC2. 

The show unit is planned around solid IC LM3914 (IC3). It drives ten LEDs by detecting simple voltage. Every LED is associated with yield of IC3 speaks to the sound level of 3 dB in dropping request from 18 to 10. The sparkling each of the ten LEDs demonstrate sound power is 30dB. The PNP transistor get base inclination when yield at stick 10 of IC3 goes low to drive the piezo ringer with a specific end goal to give sound. Ordinarily, stable force up to 30 dB is lovely. Above 80 dB, it gets to be irritating. What's more, in the event that it goes past 100 dB, it might influence your psycho motor execution, diminishing your consideration and bringing on stretch. Commotion contamination may likewise influence your listening to capacity 

Handy Tester
For novices, here's a minimal effort multicenter that can be utilized to test the state of all the electronic segments from resistors to ICs. It utilizes just a couple of segments however can likewise identify extremity, congruity, rationale states and action of multivibrators.

Straight Timer
This straightforward clock can be utilized to control any electrical machine that should be exchanged off after certain time, similar to a little warmer or a kettle, gave the hand-off switch parameters meet the prerequisites of that machine. It utilizes ease parts and joins computerized accuracy with basic simple control, giving long planning spans without the utilization of high-esteemed resistors on the other hand capacitors.