PrJSC PCF “Amplituda” has developed and manufactured the electric power supply of headlamps and auxiliary devices of mine trolley locomotives that converts DC voltage of electric-traction netware 250V into the stabilized voltage of 24 V and 12 V with load current up to 15 А.
The electric power supply IP 5 is designed for operation under environmental temperature from minus 10 to plus 35, relative humidity up to 98±2% , with moisture condensation under atmospheric pressure from 84 to 107 kPa. The environment is inexplosive, mining, current-conducting dust content up to 300 mg/m3.
The electric power supply output is short circuit protected from the side of load. IP 5 provides operation of automation and communication systems, in particular, of HF communication transport equipment of VGST type (HF public address system). It is installed wherever convenient in the driver’s cabin in vertical position, with cable entries downwards.
The power supply has successfully passed the acceptance tests at the mine “Rossiya” (SE “Selidvodugol”). Thus, the mean life exceeded 1500 h (failures were not observed during test period), the average time of operable state recovery is minimum 1 h. The average service life (designed one) with account for repairing work is 10 years.
The power supply is designed as a metal water- and dust-proof housing. Removing the upper cover gives access to the input and output connectors, as well as to the fuse-holder.
IP 5 power supply is a single-step voltage converter with forward stroke. Depending on the level of input signals, the Pulse-time modulation comparator unit generates control impulses to switch on the power transport. Operating frequency is about 40 kHz. Feed-back ensures stabilization of output voltage. In the reload mode by current the signal from the current sensor is delivered to the Pulse-time modulation comparator unit, whereby it transfers to the current stabilization mode, until the load drops.
In the short circuit mode, the comparator unit, by command of the current sensor, blocks the switching transistor, at intervals once per second, generating short test pulses. Upon elimination of short circuit, the block returns to the operating mode.
The electric power supply IP 5 is manufactured according to the Technical Specifications of Ukraine 31.4-2503132-004:2005.
Technical characteristic or electric power supply IP 5
|Nominal input voltage, V||>+75-90|
|Output stabilized voltage, V :|
|output 1 and output 2||>24±1|
|output 3||> 12±0,1|
|Nominal load current, А||> 12|
|КоэфOutput voltage pulsation factor, %,|
|Operating level of overcurrent|
|output 1||> 15—18|
|output 2 and output 3||> 1|
|Useful current, А, maximum||> 2,5|
|Coefficient of efficiency under nominal values, %, minimum||> 80|
|Overall dimensions, mm:|
|Mass, kg, maximum||> 6|