ENI-SIP Current Stabilizer

Stabilizator prądu ENI-SIP
rysunek techniczny stabilizatora prądu ENI-SIP



The ENI-SIP 110V/l-1,2A current stabilizer is intended as a power source for Hasler tachographs in locomotives and train units.


 Supply voltage  77 ÷ 137,5 VDC
 Rated output current  1,20 A
 Output current variation  0,03 A
 Ambient operating temperature  -30°C ÷ +40°C
 Weight  1,1 kg


The stabilizer is located in a metal sheet enclosure which is isolated from the electrical system. The enclosure is also the heat sink of the internal transistor and the diode within the primary circuit. The supply voltage and tachograph circuit lines are connected to the two terminal strips TLZ 4. The enclosure houses an input filter, a MOSFET power transistor, a ferrite core choke, an output filter and a control system.



The stabilizer converts the variable 77 V to 137.3 V supply voltage to stabilized 1.2 A current that is resilient to the tachograph line resistance variations. To achieve a high electric efficiency, the input voltage is converted by PWM. The supply voltage is fed to the input filter. The input filter limits the overvoltage and pulsing of the supply mains, and eliminates the stabiliser feedback to the mains. The filtered supply voltage flows to the stabiliser control system and the actuator, the MOSFET transistor. The control system switches the transistor on and off at a constant frequency of 100 kHz while adjusting the on time to produce a constant current output irrespective of the input voltage or load resistance. The transistor output is connected to an output filter, comprising anti-interference capacitors and the ferrite core choke. The filter eliminates the output current pulsing. A Hall effect measurement transducer is located between the filter and the output terminals. The device regulates the stabilizer output current and feedbacks the current value to the control system. Shorting of the output terminals does not harm the performance, since the stabilizer continuously keeps the 1.2 A output current indefinitely.


Input voltage
110 V

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