公开(公告)号：US5025195A

公开(公告)日：1991-06-18

申请号：US444289

申请日：1989-12-01

申请人： Malcolm R. Reeves

发明人： Malcolm R. Reeves

IPC分类号： G01R19/00 ,  B61L7/10 ,  G01R31/02 ,  H05B37/03

CPC分类号： B61L7/10 ,  G01R31/02 ,  H05B37/03

摘要： A circuit arrangement includes a lamp filament (1) as a load and a resistor (2) in series with the filament. For detecting the current through the load, the source of a MOSFET (6) is connected with the end of the resistor remote from the filament, the drain of the MOSFET being connected with the other end of the resistor via the primary winding of a step-up transformer (7) and a further resistor (8), a diode (9) being connected between the source and the drain of the MOSFET. If the MOSFET is turned on by an appropriate voltage at an input (11) connected to its gate, the voltage across the secondary winding of the transformer is substantially proportional to the value of the current through the filament.

公开(公告)号：US5034681A

公开(公告)日：1991-07-23

申请号：US447099

申请日：1989-12-06

申请人： Malcolm R. Reeves

发明人： Malcolm R. Reeves

IPC分类号： B61L23/00 ,  B61L1/20 ,  G01R19/155 ,  G05B9/02

CPC分类号： B61L1/20 ,  G01R19/155

摘要： A circuit arrangement for detecting an input voltage comprises an oscillator responsive to the voltage, the oscillator including a pair of transistors (8, 9) connected as an astable multivibrator, each of the transistors having a load which comprises a primary winding (16 or 17) of a current transformer (T) and a low resistance proof resistor (12 or 13). A current flows through a secondary winding (18) of the transformer the amplitude of which current is proportional to the input voltage.