Rectifier and Amplifer instruments

Rectifier and amplifier type of instruments are used and studies in the filed of instrumentation and Measurements as they provide authentic source to explore more ideas about the types and construction of such instruments

1. Department Of Electrical Engineering Batch : 15 EL Date : 13 D ecember 2016 Mehran University of Engineering & Technology SZAB Campus khairpur Mir’s

2. Subject : Instrumentation & Measurements Assigned to : Mis Kalsoom Bhagat By: Farhan Memon Rectifier and amplifier instrument

3. Rectifier type instruments are used for measurement of ac. voltages and currents by employing a rectifier element , which converts a.c . to a unidirectional d.c. and then using a meter responsive to d.c. to indicate the value of rectified a.c . The indicating instrument is PMMC instrument, which uses a d’Arsonval movement. This method is very attractive since PMMC instruments have a higher sensitivity than the electrodynamometer or the moving iron instruments. Rectifier Instruments

4. A D.C. moving-coil meter can be used to measure A.C. voltage by putting a diode or rectifier in the meter circuit.

5. Rectifier type instrument measures the alternating voltage and current with the help of rectifying elements and permanent magnet moving coil type of instruments. However the primary function of rectifier type of instruments work as voltmeter. Now one question must arises in our mind why we use rectifier type of instruments widely in the industrial world though we have various other AC voltmeter like electrodynamometer type instruments, thermocouple type instruments etc ? The answer to this question is very simple and is written as follows. 1.Cost of electrodynamometer type of instruments is quite high than rectifier type of instruments. 2.The thermocouple instruments are more sensitive than the rectifier type of instruments.

6. Half Wave Rectifier Circuits of Rectifier Type Instruments

7. Full Wave Rectifier Circuits of Rectifier Type Instruments

8. 1.The accuracy of rectifier type instrument is about 5 percent under normal operating condition. 2.The frequency range of operation can be extended to high value. 3.They have uniform scale on the meter. 4.They have low operating value of current and voltages . 5.The loading effect of an ac rectifier voltmeter in both the cases (i.e. half wave diode rectifier and full wave diode rectifier) is high as compared to the loading effects of DC voltmeters as the sensitivity of the voltmeter either using in half wave or full wave rectification is less than the sensitivity of DC voltmeters. Advantages of Rectifier Type Instruments

9. An instrument amplifier is an electronic device which converts the often barely audible or purely electronic signal of a musical instrument into an audible sound. An instrument amplifier is used with musical instruments such as an electric guitar, an electric bass, electric organ, synthesizers and drum machine to convert the signal from the pickup (with guitars and other string instruments and some keyboards) or other sound source ( e.g , a synthesizer's signal) into an electronic signal that has enough power, due to being routed through a power amplifier, capable of driving one or more loudspeaker that can be heard by the performers and audience. A mplifiers Instruments

10. Instrument amplifiers are available for specific instruments, including the electric guitar, electric bass, electric/electronic keyboards, and acoustic instruments such as the mandolin and banjo. Some amplifiers are designed for specific styles of music, such as the "traditional"-style "tweed" guitar amplifiers, such as the Fender Bassman used by blues and country music musicians, and the Marshall amplifiers used by hard rock and heavy metal bands .

11. Types Guitar amplifiers Bass keyboard amplifier