E-1282 Electronic Medical Equipment

Hall Effect:
Aim: Practical Physics Object
Apparatuses Required:

Electromagnet: For Magnetic Field

Power Supply: For Magnet

Hall Effect Set-up: For Hall Probe

Hall Probe P type: For above

Hall Probe N type: For above (Optional)

Digital Gauss Meter: For Measuring Magnetic Power with Probe
EMU - 50:
EMU - 50 have the most widely used 'U' shaped soft iron yoke. The soft iron is of a special quality, structurally uniform, well machined and finished to meet the rigid standards.
The pole pieces are made from dead annealed soft iron blocks of the best quality available. They are well shaped, machined and finished. Normally flat pole pieces are supplied.
The coils are wound on non-magnetic formers with uniform layers of D.C.C. copper wire. The new and modern design of the coils provides good thermal conductivity characteristics and eliminates trouble same hot spots even at high magnetic fields.
Specifications:
Field Intensity: 11 Kg + 5% with 10 mm air-gap. The air-gap is continuously variable upto 75 mm with two way knobbed wheel screw adjusting system.
Pole Pieces: 75 mm diameter. Normally flat faced pole pieces are supplied with the magnet.
Energising Coils: Two, each coil is wound on non-magnetic formers and has a resistance of about 12 ohms.
Yoke Material: 'U' shaped soft iron.|
Power Requirement: 0 - 9 V @ 3.5 A, if coils are connected in series.
0 - 45 V @ 7 A, if coils are connected in parallel.
Weight: 81 Kg.Subject to Change.
DPS - 50:
DPS - 175 is designed to be used with the electromagnet, model EMU - 50 as a constanct current power supply to generate magnetic field upto 11 KG. The current requirement of 3.0 A per coil, i.e. a total of 6 A was met by connecting six closely matched constant current sources in parallel. In this arrangement the first unit works as the 'master' with current adjustment control. All others are 'slave' units generating exactly the same current as the master. All the six constant current sources are individually IC controlled and hence result in the highest quality of performance. One advantage of this arrangement is that if a particular constant current source develops a fault, still the remaining channels would continue to operate albeit with a reduced maximum current capability. The supply is protected against transients caused by the load inductance.
Applications: Power source for electromagnets having coil resistance upto 12 ohms per coil. Reduce current for higher resistance coil. Suitable for other loads in the range 10 - 12 ohms only.
Specifications:
Current Range: Smoothly adjustable from 0 - 3 A per coil, i.e. 6 A.
Load Regulation: 0.1% for load resistance variation from zero to maximum.
Line Regulation: 0.1% for + 10% mains variation.
Protected: Electronically protected against overload or short circuit.
Display: 3½ digit, 7 segmet LED DPM.
Power: 220 V + 10%, 50 Hz.
Hall Probes:

Hall Probe (Ge Crystal)
Ge single crystal with four spring - type pressure contacts is mounted on a sunmica - decorated bakelite strip. Four leads are provided for connections with measuring devices.
Technical Details:
Resistivity: 8 - 10 ohms cm
Contacts: Spring type (solid silver)
Zero-Field Potential: 1 mV (adjustable)
Hall Voltage: 25 - 35 mV / 10 mA/KG
It is designed to give a clear idea to the students about Hall Probe and is recommended for class room experiment. A minor drawback of this probe is that it may require zero adjustment. Ge single crystal n or p-type as desired.

Hall Probe (lnAs) Imported Hall Element:
Indium Arsenide crystal with 4 soldered contacts (Imported) is mounted on a PCB strip and covered with a protective layer. The Hall Element is mounted in a pen-type case and a 4-core cable is provided for connections with the measurig device and current source.
Technical Details:
Contacts: Soldered
Rated Control Current: 4 mA
Zero Field Potential:< 4 mV
Linearity (0 - 20 KG): + 0.5% or better
Hall Voltage: 60 - 70 mV / 4 mA/ KG
The crystal alongwith its four contacts is visible through the protective layer. This is mainly used as a transducer for the measurement of magnetic field.
DHE - 21:
DHE - 21 operates on the principle of Hall Effect in Semi-conductors. A semi-conductor material carrying current develops an electro-movie force, when placed in a magnetic field, in a direction perpendicular to the direction of both electric current and magnetic field. The magnitude of this e.m.f. is proportional to the field intensity if the current is kept constant, this e.m.f. is called the Hall Voltage.
This small Hall Voltage is amplified through a high stability amplifier so that a millivoltmeter connected at the output of the amplifier can be calibrated directly in magnetic field unit (gauss).
Applications:

Wide application in industry where accurate measurements of magnetic field is required.

Measurement of steady magnetic field e.g. in loud speakers, dynamos, moving coil instruments etc.

Useful in laboratory experiments involving electromagnets.
Specifications:
Range: 0 - 2 KG & 0 - 20 KG
Resolution: 1 G at 0 - 2 KG range
Accuracy: + 0.5%
Temperature: Upto 50°C
Display: 3½ digit, 7 segmet LED DPM
Power: 220 V + 10%, 50 Hz
Tansducer: Hall Probe with an imported
Hall Element:
Special Feature:
Indicate the direction of the magnetic field Subject to change.