Electricity

ELECTROSCOPE PITH BALL TYPE

3134-01

For demonstrating the attraction and repulsion of electric charges. Consists of a an insulated brass pillar and hook on a base. Supplied with two colored pith balls with strings attached.

PITH BALL, SPARE

3134-02
For electroscope pithball type as described above. Pack of 10.

WHEATSTONE BRIDGE, SLIDE WIRE FORM, FOUR GAPS TYPE

3143-01

Improved version of simple meter bridge. For precise measurement of an unknown electrical resistance and for comparing nearly equal resistances without determination of the end-resistances.

Comprised of a hardwood base 1.1 meter long with laminated top and plastic feet. A meter long constantan resistance wire, 24swg, is stretched along a meter scale graduated in millimeters fitted on this base. Each end of the wire is firmly and precisely attached to plated copper strips. Three more copper strips are fixed parallel to the wire providing four gaps. Electric connections are made through 4mm socket binding post terminals. Supplied with a knife- edge jockey to make contact with resistance wire and the galvanometer (not supplied).

PENCIL JOCKEY (KNIFE EDGE JOCKEY)

3143-02

For wheatstone bridges and potentiometers. A brass metal knife edge is mounted on one end of an insulated handle with a 4mm socket binding post terminal on the other end. Overall length 100mm. Pack of 10 pieces.

CONTACT TAP KEY (TAPPING KEY)

3144-01

For providing momentary contact in electrical circuits which are normally open. Can also be used in morse code applications. Consists of a bakelite base with two 4mm socket binding post terminals. Circuit is closed with plated spring hard brass strip with insulated knob. Silver contacts.