Various diagram: meter

Showing posts with label meter. Show all posts

Sunday, November 9, 2014

LED Volt Meter Circuit

Here is a Simple LED Volt meter to Monitor the charge level in Lead Acid Battery or Tubular battery. The terminal voltage of the battery is indicated through a four level LED indicators. The nominal terminal voltage of a Lead Acid battery is 13.8 volts and that of a Tubular battery is 14.8 volts when fully charged. The LED voltmeter uses four Zener diodes to light the LEDs at the precise breakdown voltage of the Zener diodes. Usually the Zener diode requires 1.6 volts in excess than its prescribed value to reach the breakdown threshold level. When the battery holds 13.6 volts or more, all the Zener breakdown and all LEDs light up. When the battery is discharged below 10.6 volts, all the LEDs remain dark. So depending on the terminal voltage of the battery, LEDs light up one by one or turns off.

Circuit diagram:

LED Volt Meter Circuit Diagram

Wednesday, October 22, 2014

Simple Meter Impedance Speaker Circuit Diagram

A simple impedance meter can be useful to measure the actual impedance of a speaker or headset, ideal for anyone working with sound, making and repairing speakers. This impedance meter works in conjunction with a multimeter or oscilloscope to measure the impedance.

Meter Impedance Speaker Circuit Diagram

How to make the measurement of impedance speaker with the multimeter

Connect a digital multimeter to AC voltage in the range of 200mV.
Connect the device under test terminals
SW1 to R7, if the value of the measured impedance is less than 100 ohm R8 or upwards.
With SW2 in the "Set" power-on circuit through SW3
Adjust P1 to read exactly 100.0mV the display DVM
Switch SW2 in the "Measure" and read directly from the speaker or headphones impedance value on the display DVM, eg 8.2mV = 8.2 Ohm / 80.1mV = 80.1 Ohm

How to make the measurement of impedance speaker with the oscilloscope:

Connect the oscilloscope instead of DVM (multimeter) and turn P1 fully clockwise.
Short the output speaker and adjust R3 to get a sine wave amplitude of about 2.2V peak-to-peak.
How to make the impedance measurement Speaker "By ear"

Connect a small speaker or headphones, forming a pair of headphones to the output of the circuit and turn P1 to obtain a level of sound output moderated. Carefully adjust R3 until the output sound stops, then turn the trimpot to adjust slowly and stop immediately when the sound start again.

List of components

P1 4K7 linear potentiometer
R1 12K 1/4W Resistor
R2 2K2 1/4W Resistor
R3 1K 1/2W Trimmer (cermet)
R4 1K5 1/4W Resistor
4K7 1/4W Resistor R5
R6 3K3 1/4W Resistor
R7 100R 1/4W Resistor (See Notes)
R8 1K 1/4W Resistor (See Notes)
R9 1K 1/4W Resistor (Optional)
22NF 63V Polyester Capacitor C1
C2 330nF 63V Polyester Capacitor
C3 22μF 25V Electrolytic Capacitor
D1, D2 1N4148 75V 150mA Diodes
D3 3mm red LED (Optional)
Q1, Q2, Q3 BC550C 45V 100mA Low noise High gain NPN
IC1 78L05 5V 100mA Regulator IC
SW1, SW2 SPDT Toggle or Slider
SW3 SPST switch or Slider
B1 9V PP3 battery for PP3Clip

Notes:

For very precise measurements using resistors R7 and R8 with 1% or 2% tolerance.
D3 LED pilot and his current limiting resistor R9 are optional.

Monday, October 20, 2014

TV Relative Signal Strength Meter

This circuit was designed to assist the installation of TV antennas. The signal is monitored using a small portable TV set and this circuit monitors the output of the TVs FM detector IC via a shielded lead. To initially calibrate the meter, adjust trimpot VR2 to zero the meter. Trimpot VR1 is a sensitivity control and can be set for a preset reading (ie, 0dB) or can be calibrated in millivolts. Rotating the antenna for a minimum reading on the meter (indicating FM quieting) gives the optimum orientation for the antenna.

Circuit diagram:

TV Relative Signal Strength Meter Circuit Diagram

Friday, September 5, 2014

Simple Audio power meter

This is simple audio power meter.When you use high power speakers this schema is so important Because you can keep your speakers without burning.Here When the speaker out puts 1W green color LED will light up,for 1.5W you will be able to see orange color,When speaker out puts more than 3W you will be able to see red color.

Note

# The power levels mentioned are valid for 4-Ohm speakers. For 8-Ohm speakers you have to divide all the resistor values by two

# this schema cant drive more than 40W continuously.

# If you want more LEDs you can attach LEDs as the same way

Thursday, August 21, 2014

Simple Electro meter circuit

This is a simple electro meter schema.This schema will detect electrostatic charge from the any material such plastic,comb etc.

It can measure up to 30 cm from the target material.
To use this schema first adjust R2 when the antenna near the material until Amp meter read 1 mA.

Friday, August 15, 2014

Precision Audio Milli volt meter Circuits Wiring diagram

This electronic schema is audio milivolt meter. It measures 10mV to 50Volt RMS in eight ranges.

Precision Audio Millivoltmeter Circuits Diagram

Precision Audio Millivoltmeter Circuits Diagram

Notes:

Connect J2 and J3 to an Avo-meter set to 50µA range:
Switching SW2 the four input ranges will be multiplied by 5
Total fsd ranges are: 10mV, 50mV, 100mV, 500mV, 1V, 5V, 10V, 50V
Set R11 to read 1V in the 1V range, with a sine wave input of 1V @ 1KHz
Compare the reading with that of another known precision Millivoltmeter or with an oscilloscope.
The oscilloscope reading must be a sinewave of 2.828V peak to peak amplitude
Frequency response is flat in the 20Hz-20KHz range
If you have difficulties in finding resistor values for R1, R2, R3 & R4, you can use the following trick:
R1 = 10M + 1M in parallel
R2 = 1M + 100K in parallel
R3 = 100K + 10K in parallel
R4 = 1K2 + 6K8 in parallel
All resistors 1/4W 1% tolerance

Parts:

R1_____909K    1/2W 1% Metal Oxide Resistor

R2______90K9   1/2W 1% Metal Oxide Resistor

R3_______9K09  1/2W 1% Metal Oxide Resistor

R4_______1K01  1/2W 1% Metal Oxide Resistor

R5_____100K    1/4W Resistor

R6_______2M2   1/4W Resistor

R7______82K    1/4W Resistor

R8______12K    1/4W Resistor

R9_______1K2   1/4W Resistor

R10______3K3   1/4W Resistor

R11____200R    1/2W Trimmer Cermet

C1_____330nF   63V Polyester Capacitor

C2,C3__100µF   25V Electrolytic Capacitor

C4_____220µF   25V Electrolytic Capacitor

C5______33pF   63V Polystyrene Capacitor

C6_______2µ2   63V Electrolytic Capacitor

D1-D4___1N4148 75V 150mA Diodes

IC1_____CA3140 Op-amp

IC2_____CA3130 Op-amp

SW1_____2 poles 5 ways rotary switch

SW2_____SPDT switch

J1______RCA audio input socket

J2,J3___4mm. output sockets

B1______9V PP3 Battery

Clip for PP3 Battery

Monday, August 11, 2014

TV Relative Signal Strength Meter

This schema was designed to assist the installation of TV antennas. The signal is monitored using a small portable TV set and this schema monitors the output of the TVs FM detector IC via a shielded lead. To initially calibrate the meter, adjust trimpot VR2 to zero the meter. Trimpot VR1 is a sensitivity control and can be set for a preset reading (ie, 0dB) or can be calibrated in millivolts. Rotating the antenna for a minimum reading on the meter (indicating FM quieting) gives the optimum orientation for the antenna.

Circuit diagram:

tv-relative-signal-strength-meter-schema diagram1

TV Relative Signal Strength Meter Circuit Diagram