[Elecraft] Samlex SEC-1223 switching PS-Output voltage adjustment?

[John Webster]

Does anyone know if one can adjust the output
voltage of a Samlex SEC-1223 from 13.8 to
14 or 14.2volts?

[Purpose, is to float charging the K2's internal 
battery while running the K2 with its QRP top.
Of course, it will also power the K2 with the 
KPA100 top in place, as an alternate duty.]

There are two trim pots (marked VR1 "501" and 
VR2 "102", glued down, but adjustable I think). 
There is NO circuit description or diagram in the brief 
manual! All it says is that its 13.8 VDC is based 
on pulse width modulation (PWM) control. 
Anybody know if I can safely adjust the output? 
Has anyone done this with the unit? If so which pot? 
Can I safely experiment with the two pots? 
I don't really know how PWM PS's work. 

Any help would be gratefully received! 

Thanks,

John, N6JW