---- July 20th 2024 ----

CAGE Code: 5DME2
ITAR Registration Code: M28889
Call: 1 (800) 377-3244
Monday to Friday 8 A.M. - 5 P.M. (Pacific Time)
E-mail questions and requirements to: sales@coilws.com

Pricing is subject to change depending on product availability and backorders.
*Please Note: Items without price are listed for CWS' capability purposes.

Vehicle Battery Noise Filters

The EMI-P30A and EMI-P50A are 30 amps and 50 amps low pass Power Line Filters respectively. Low pass filters are used in many different applications. In radio frequency applications, low pass filters are usually designed using inductors and capacitors. These filters are used to filter out unwanted signals that may be present in a band above the wanted pass band.
The EMI-Pxx series from Coil Winding Specialist (CWS) are designed to allow low-frequency audio signals to pass, but attenuates signals with frequencies higher than the cutoff frequency. These filters are design in a Pi network configuration.
Radio communications are widely used in law enforcement and first responder vehicles to communicate among themselves and to the police stations or hospitals. These radios in Police Cars, Police Motorcycles, Ambulances, Fire Trucks, Rescue Vehicles and other First Responder vehicles are all connected to the vehicle’s battery.
Other devices in the vehicles such as turn signaling lights, head lamps, search lights, AM/FM Radios, DVD players, on board computers and other electronics are also connected to the same vehicle battery. The noises emitted by these devices will interfere with the Radio transmissions over the air.
By installing the EMI-Pxx series between the Radio equipment and the battery, noises from other devices are prevented from interfering with the Radio communications. The EMI-Pxx series have mounting holes for direct mount to the vehicle chassis. The Positive Terminal of the battery is connected to the +Batt of the EMI-Pxx filter, and the Radio’s positive terminal is connected to the Radio terminal of the filter. In this way, the battery power for the Radio is isolated from other potentially noisy devices.

EMI-P30A is rated for 30 amps of continuous operation. The EMI-P30A has been in field use by law enforcement and first responder vehicles for many years and many thousands have been shipped around the world.
Following a request from Motorola Radio Division on a requirement for a 50 amps device for its Radios, CWS has released the 50 amps, EMI-P50A filter. As radios gets more and more sophisticated and more powerful, it also consumes more current.
The EMI-P50A is rated at 50 amps of continuous operation. This higher current filter is currently in full production.

Both the EMI-P30A and EMI-P50A are readily available from CWS and can be shipped immediately from stock. To order the parts, please click "Add to Cart" button in the table below.

- Reduce Audible Noise Interference from Vehicle Batteries in Radio,CB,HF,VHF and UHF Communications.
- Direct Mounting onto Police Cars and Motorcycles, Ambulances, Fire and Rescue Trucks, Trailer Trucks, etc.

- Flyer
- Wiring Diagram for EMI Filters

Part Number Inductance Current, Amp Quantity
on hand
EMI-P30A 40uH   45 $58.00
Buy Now
EMI-P50A 40uH   3 $56.00
Buy Now

Disclaimer: Coil Winding Specialist, Inc., its affiliates, agents, and employees acting on behalf of Coil Winding Specialist, Inc. (collectively, CWS) disclaim any and all liability for any errors, inaccuracies or incompleteness contained herein or in any other disclosure relating to any product. CWS reserves the right at any time and from time to time to make changes to design, technical specification, or construction of any product listed on this website without notice. CWS also reserves the right to discontinue or limit sale of any product or service available throughout this website on temporary or permanently basis without notice. CWS highly recommends customers not to use its products offered on this website for inappropriate use and applications. Products should be tested for its suitability by prospective customers in all possible applications and conditions. Customers using or selling CWS products for use in other than recommended applications do so entirely at their own risk and agree to fully indemnify CWS from any damages arising or resulting from such use or sale.

WARNING: This product can expose you to chemicals which is [are] known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go towww.P65Warnings.ca.gov.

Any Comments, Suggestions or Questions? Contact us!
Email: sales@coilws.com
CWS 353 West Grove Ave. Orange, California 92865
Call us Toll Free: 1-800-679-3184 or 1 (800) 377-3244

Tel: (714) 279-9010, Fax: (714) 279-9482

Copyright 2008, Coil Winding Specialist, Inc
Updated July, 2013

CAGE Code: 5DME2(Registered with www.ccr.gov)