Transmitter uses liquid cooling in power amplifier

Thanks to perfect timing by our local sales office, CEJN was able to offer a coupling solution to ensure better liquid cooling of the PCB than previous suppliers. We started delivery of the Non-Drip Series 567 in 2012 to a customer in the broadcasting and telecommunications sector. The company designs and manufactures the core of the network: the transmitter.

Non-Drip Series cools PCB
On top of the power amplifier module sits the PCB (printed circuit board), which reaches very high temperatures during operation. To effectively cool transmitters above 7kWrms, liquid cooling of the high-power amplifier module takes place inside. There are two sets of Non-Drip components on each module. When the unit is inserted, a Non-Drip 567 nipple connects to a Non-Drip 567 coupling installed on the back side of the rack, enabling 100% spill-free mixing of water and ethylene glycol to cool the system. This is all done at a pressure of about 5 bars.

coupling used to cool power amplifierBlind-mate functionality
Normally our Non-Drip series is disconnected by hand, however, here a blind-mate function is employed. If not properly inserted, the module will not function and cooling will be at a standstill. During disconnection the Non-Drip module is disconnected by means of this push-pull function. The locking sleeve, mounted on the rack, automatically releases the coupling when the module is pulled. 

EPDM seal to withstand ethylene glycol
Since previous designs had used ethylene glycol, the customer wanted to continue using this particular coolant in the newly-designed TV transmitter. To make sure the sealant could handle this liquid, CEJN proposed the use of EPDM as a sealing material. EPDM provides outstanding resistance to aging, long-lasting flexibility and elasticity with good tensile strength, making it unique.

Secure delivery
The customer is very satisfied with the solution. Since implementation there have been no problems with either delivery or function. We hope CEJN will be the natural choice for this customer for all future designs using liquid cooling.