What is “Lean Charge”? Inside the Daystate CDT System.

Tuesday, May 16, 2006

As the new Mk3′s and Air Wolf’s arrive, the new concept of what Daystate refers to as ” Lean Charge” is leaving some in the dark about what exactly is so great about the new electronic firing system which Daystate has developed for their Electronic Series of airguns. The following is a brief explanation from David Snook, one of the instrumental minds behind the CDT system found inside the Daystate rifles:

“The original CDT units used a 7ms pulse where the voltage was adjusted to vary the power. This results in the valve being opened in a similar manner to a hammer and weight, where the valve is opened by the potential energy contained in the moving armature. I call this a “ballistic” valve.

Lean charge uses a different concept, it uses the maximum voltage level (approximately 70V) and adjusts the energy using the applied current pulse length, this can be between 1200us to 5800us depending on power level and solenoid design. This uses a combination of ballistic and magnetic valve opening and timing. The potential “ballistic” energy of the armature “knocks” open the valve and then the magnetic field sustained by the current pulse length determines how long it is kept open for. This has the following advantages:

1. The initial acceleration of the armature is greater due to more current being applied to the solenoid.

2. In turn the valve opens faster giving a steeper barrel pressure rise time.

3. The solenoid is then switched off allowing the valve to close rapidly under the air pressure behind it, rather than waiting for a ballistic hammer to decelerate and then close. This action allows the natural self-regulating properties of the valve to be more effective and gives a sharp pressure fall time saving air use.

4. The valve is opened and closed when the pellet is still in the barrel, this is difficult to achieve with a totally ballistic valve operation.

5. Muzzle energy can be tightly controlled using this technique.

The overall benefits are very fast lock times (typically less than 7ms), excellent air economy with attendant large shot capacity and reduced muzzle blast giving a very much quieter gun. The most surprising benefit is accuracy, where reduced blast lessens destabilisation effects on the exiting pellet.

Shooting a high powered lean charge gun is a culture shock, even with a very modest silencer it is a fast, quiet and very accurate gun.”

m4s0n501

Leave a Reply