UPS (Inviter) System, Square wave 0.5 KVA to 5 KVA Dear Sir,  We are interested in UPS (Inviter) systems 0.5 KVA to 5 KVA. We need for electricity good Invert (UPS) system with 12V,DC 24V or 36V with auto transfer from AC to Inversion (Inviter) for Long Back-Up Time.  UPS (Invert)  UPS (Invert) OFF Line system we need as under: Max. Output Power ( Proximate )  (W): (a) 500W , (b) 750W, (c ) 1000W (d) 1.7KvA/1200W DC Mode(V) : 12V-DC 12V-DC 24V-DC 24-V-DC Input Voltage(V) : 180 to 270 V 50 Hz Output Waveform : Square wave or Step wave or modified Sine wave General Pro Charge Current(A): 5 / 15 A . Auto Charging on AC Transfer Time : 8 to 10 ms Cooling Fan : AC and DC (Work on both) Our weather is Very Hot ( Temp. 40 C to 48 C ) so we need Good Cooling run on both AC. and DC. Operation.  - Possible to Add External Battery back-up PARTS for UPS We are also need parts for UPS, like  a) Transformer  b) PCB (frequency plate with auto Battery charging and Low Battery Cut-OFF, etc.  we are attaching here specification 4 type Transformers. Controlling PCB (frequency plate with auto Battery charging and Low Battery Cut-OFF, etc.) Square wave or Step wave, you may suggest some PCB which we can use with these Transformers. We need these all for push and pull full wave Technology Inverts. We will be highly oblige, if your good selves send us prices and also details information for your complete range of products.  Your kind co-operation and early reply will be highly appreciated.  Thanks and regards.  M A Ramay  3A Enterprise  295 A Upper Mall,  Lahore-54000, PAKISTAN.  TEL #: 92-42-5754112  Mobil: 03009434941-  Fax #: 92-42-5712685