DC Power and Noise
All the standard Kemo products are available with DC power input for portable applications.
Typically 9 - 30 V DC power input, where 12 V or 24 V DC is available from batteries or a vehicle supply.
Generally most DC powered units use DC - DC converters, these are switching devices and they generate high frequency switching energy. Depending on the devices used and their type the level of this energy varies, but in low quality units it can be several volts on a typical unsmoothed 15 volt supply. ( We have seen this in non Kemo systems) The energy is typically a high speed switching pulse of several MHz frequency content which repeats at about 100 kHz. This energy will get into most signal circuits as some of the content can be radiated as well as conducted. As DC - DC converters become more efficient the switching edges become good broad band noise generators.
We use a number of techniques to minimise this noise.
Kemo uses good quality DC-DC converters from reputable and stable manufacturers. Then we use the best practice possible in our circuit board layouts, and wiring. We use best practice input and power filtering around the DC-DC converters. For best performance (our permanent target) we often add local screening. Typically we attenuate any DC-DC power noise by a factor of over 50 (-64dB). However some of this energy may get into the signal paths, and may be seen as high frequency 'noise'.
So if you require a portable system, there may be a higher noise level than with a 'mains' powered unit. Our experience is that in low frequency (<20kHz) systems with signal levels above about 50mV DC-DC related issues are not a problem.
IF in doubt - contact us to discuss your application, we have probably done it before in our long history.