Friday, May 3, 2013

Regel System PulseGuide Illuminator Hack

I found that my new Regel System PulseGuide illuminator is a superb little device (photo #1), however for my viewing purposes I found it to be a little on the dim side.  Now comes the hack.  I was planning on replacing the TS555 CMOS clip, but to use a regular LM555, the minimum input voltage was 4.5 Vdc.  The supplied battery is a CR 1/3 N at 3 Vdc.  If you short out the 51 ohm resistor next to the chip, the LED will become brighter, but the flash control barely works (photo #2).  The 555 CMOS chip is good up to 16Vdc input.  By replacing the original battery with four separate batteries, 3 being LR1130 (35mAh 1.5 Vdc), & 1 BR1216 (25mAh 3Vdc) The two main reasons for the four batteries is because by only placing 3- LR1130's in the battery compartment they did not fill the space and the positive & negative terminals would have to be slightly pried open to fill the void.  By adding the forth battery (BR1216) not only filled this small void, to which that battery is half the thickness of the others, it also added an additional 3Vdc, still well within the operating range of the TS555.   By increasing the voltage output from 2.9 Vdc to approximately 7.5 Vdc, now with a significant increase in voltage, and placing a jumper across the current limiting 51 ohm resistor, the tuning circuit of the flash still works very well (photo #3).  Now the potentiometer (on/off switch) still has full control and even turned down to the lowest setting, there is still plenty of brightness.  After this modification and the increase in voltage I seen no reason to go to the extent of replacing the original TS555 chip.



Leon Palmer
May 5
to me
Hello Mr. Pyles,

Thanks for the kind words!  Typically if the pulsguide doesn't light the reticle, its because the reticle glass plate is not aligned with the illumination slit at the bottom of the 8mm hole in the side.  Sometimes this can be solved by making sure LED goes all the way in a bit further (unplug led from socket, rebend the leads so it pokes out a bit further).

But your solution is quite clever!  I use CMOS because lithium is only 3 volts, and TTL  555 will not work down to 3 volts.

best regards






Mr. Palmer, Thank you very much for reading my e-mail.  I didn't mean any disrespect by re-working your PulseGuide system.  You do have a very superb product.  You are right about the glass plate in the reticule being out of alignment.  But you know how the old saying goes, "Necessity is the mother of invention".  As I previously stated, you people have some wonderful products to which I will be purchasing some of them very soon. If in the future if you have the need for some in the field trial tests, please feel free to give me a shout, I and Sunset Observatory would thoroughly enjoy be part of your R&D program. Thanks again.  Don Pyles.  Sunset Observatory



May 5


Leon Palmer
May 5
to me
Hi Don,

No offense taken, always accept suggestions (working one now with another customer on nSTEP who offered a good design change).  I've done a motor kit for your vixen scope (for a previous customer), so that's pretty easy.  Photo shows the stepper version.

best regards,

For more information about this cool little device in it's original state, please visit the following links,



                             http://www.optcorp.com/ri-pulsguide-pulseguide-illuminator.html