describe the working principle of synchroscope and phase sequence indicator
Synchroscope A polarized-vane synchroscope has a field winding with a phase-shifting network arranged to produce a rotating magnetic field. The field windings are connected to the "incoming" machine. A single-phase polarizing winding is connected to the "running" system. It is mounted perpendicular to the field winding and produces a magnetic flux that passes through the moving vanes. The moving vanes turn a shaft that carries a pointer moving over a scale. If the frequency of the source connected to the polarizing winding is different from the source connected to the field winding, the pointer rotates continually at a speed proportional to the difference in system frequencies (the beat frequency). The scale is marked to show the direction of rotation corresponding to the "incoming" machine running faster than the "running" system. When the frequencies match, the moving vanes will rotate to a position corresponding to the phase difference between the two sources. The incoming machine can then be adjusted in speed so that the two systems are in phase agreement.
Pulse In medicine, a pulse represents the tactile arterial palpation of the heartbeat by trained fingertips. The pulse may be palpated in any place that allows an artery to be compressed near the surface of the body, such as at the neck (carotid artery), wrist (radial artery), at the groin (femoral artery), behind the knee (popliteal artery), near the ankle joint (posterior tibial artery), and on foot (dorsalis pedis artery). Pulse (or the count of arterial pulse per minute) is equivalent to measuring the heart rate. The heart rate can also be measured by listening to the heart beat by auscultation, traditionally using a stethoscope and counting it for a minute. The radial pulse is commonly measured using three fingers. This has a reason: the finger closest to the heart is used to occlude the pulse pressure, the middle finger is used get a crude estimate of the blood pressure, and the finger most distal to the heart (usually the ring finger) is used to nullify the effect of the ulnar pulse as the two arteries are connected via the palmar arches (superficial and deep). The study of the pulse is known as sphygmology.