|
US3012196A
|
|
Multi-range alternating current measuring devices
|
|
US2882496A
|
|
Electrical measuring devices
|
|
US2619576A
|
|
Soldering iron
|
|
US2500541A
|
|
Inertia-type electromechanical sound transducing device
|
|
US2400112A
|
|
System for measuring differences of potential
|
|
US2255249A
|
|
Voice translating apparatus
|
|
CA555149A
|
|
Bone-conduction hearing devices
|
|
CA641077A
|
|
Electric measuring devices
|
|
CA623864A
|
|
Multi-range alternating current measuring device
|
|
CA504221A
|
|
Electrical measuring instruments
|
|
CA747527A
|
|
Electric current measuring device with coil deflection stops
|
