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CED 4001-16 Mains Pulser

The CED 4001-16 Mains Pulser generates mains-frequency-locked pulses that can be used to reduce the magnitude of mains pickup (‘hum’) in recorded signals. The output is on a BNC connector, double-isolated from mains and consists of a train of 150 microsecond positive-going 5V TTL pulses, suitable for direct connection to a 1401 Event input.

The Mains Pulser will run off any mains supply between 100 -240 V AC, 50 - 60 Hz. The case is earthed to mains earth. Current consumption is less than 100 mA.

Box size: 104mm x 126mm x 53mm (W x D x H).

How to use the Mains Pulser

The recommended method of use is to record the pulses on an Event channel, alongside the waveform signal. Hum removal can then be done off-line, for example by using the Spike2 scripts HumRemove or HumRemoveExpress. Averaging with respect to the mains-generated pulses gives a good copy of the hum component, which can be subtracted from the polluted signal to provide a cleaner version. Click on the video tutorial on the right for a demonstration.


Click to view video

This video tutorial shows you how to remove mains hum with the HumRemoveExpress.s2s script and a 4001-16 Mains pulser


Mains ‘hum’ is often complex and composed of odd harmonics of the mains frequency, making it very difficult to remove or suppress using simple high pass or notch filters. HumRemoveExpress.s2s is a Spike2 version 7 script that you can use offline to strip out much of this residual mains interference, making your data much more presentable and easier to analyse. This video tutorial shows how to use the script to remove mains hum.

Cambridge Electronic Design Limited

Registered in England: 00972132

Registered office:

  • Cambridge Electronic Design Limited,
  • Technical Centre,
  • 139 Cambridge Road,
  • Milton,
  • Cambridge CB24 6AZ

VAT: GB 214 2617 96

Producer registration number: WEE/BD0050TZ

Terms and Conditions of Sale

For our US customers, we can provide tax form W-8BEN, that identifies us as a UK company.

DUNS: 219151016
NAICS: 423490
Commodity codes
Hardware: 84716070
Software: 85235190

By email:


By post:
  • Cambridge Electronic Design Limited,
  • Technical Centre,
  • 139 Cambridge Road,
  • Milton,
  • Cambridge CB24 6AZ
By telephone:

(Int.+44) (0)1223 420186

From North America (Toll Free):

1 800 345 7794