Highlights:

• Audiograde Quality Soft start Board
• High Quality Components Used Throughout
• No soldering Required, All connections are Spade Type / PBT PCB connectors
• Can Support Dual 600 watts transformers

Description:
The linear power supplies normally used in Audio Power amplifiers draw a very large but brief current when they are first turned on. This is due to the use of smaller magnetic cores inside the transformers which results in what is known as high 'inrush' current at power up.
 This large current can eventually damage the bridge rectifier and filter capacitors as well as produce a 'thump' in the speaker. 

This soft start circuit can be installed in the mains supply to an Audio Power Amplifier to address this problem. It will limit the initial current flow by using four robust NTC thermistors in series with the mains supply. 

Features of this Version:
This high quality circuit board is based on the IC chip UPC1237 as the main Output device. This chip controls the operation of two 16 A relays that route the mains supply voltage through a group of 4 NTC thermistors. This limits the initial current flow to the transformer of your Amplifier and thus protects the bridge rectifier / filter capacitors .During the turn-on period when the mains current flows through these thermistors they may heat up a little - this is normal and not an indication of any problems with the circuit. This board does not require high voltage to be carried on the device's front panel for switching purposes. This is because this circuit has been designed to be operated by a Low DC voltage, that can be easily  routed to a Low current type (3A / 5A) latching switch

Part Details:

PCB Type : 2MM thick FR4 grade Double sided glass-reinforced epoxy board with 2 OZ copper foil thickness on both layers. 

Relays: Hi Quality  OMRON G2R-1E 16A X 2 with Silver Cadmium Oxide contacts (designed to handle high in rush current ) the cost of a single relay is US$ 4.0 ~ 5.5 

"Green Cube" M Series Sealed Type PCB mountable transformer from BingZi

Samsung / Nichicon capacitors / Vishay Resistors

Switch Required : SPST latching type ( ALL of our led ring type latching switches are compatible with this board ) 

Specifications:
PCB size : 120mm x 100mm
PCB thickness : 2mm
Max Component Height :26 mm
Recommended Max current Handling : Can support 2 x 600 Watts transformers 
Switch Type: Low current 3A or 5A SPST latching type ( ALL of our led ring type latching switches are compatible with this board .Please see the related products tab for all Supporting accessories)
Delay : 3 secs

Whats Included:

Main Soft Start Board - 1 Pc
Insulated Female disconnects - 6 Pcs
M3 type Brass PCB mounts 5mmX8mm - 4 Pcs
M3 Screws - 4 Pcs