power supply

[Arthur Alchin]

I have a small 750w (GMC) generator that I wish to use for power in the field for the telescope/ computer.

The power is dirty so therefore have invested in a filter board from DSE that cost about $110 (dearer than the generator) i did want an invertor but the price was too heafty.

Only problem is that I need to keep the revs up on the Genie so that it supplies enough current to activate the circuitry on the filter board.

The genie appears to have an auto throttle that responds to power needed and at present I have a 25w red light globe attached but unfortunately not enough to trigger the throttle.

Anybody with similar experience that can help, I don't want to have to add to many lights otherwise will end up like a circus. Any ideas for maybe a 100w dummy load etc.

Arthur

[montewilson]

An electric blanket might be an option. It wont burn anything or make light or noise. In the meantime get anything that will give you the load you want and test the rig at home.

I used one of those generators for more than a year and it worked OK for my computers without any kind of filter.

It seems a pity to have to add a load to get it to work....

Do you have a link on the DSE site for the filter? I am keen to understand what it does exactly.

[Omaroo]

I absolutely agree with Monte. Load it with a 50w blanket or something. Only when mine has a 50 or 60 watt light globe going does it settle down into a groove. Once it's there it's quite stable. Power from these is typically very dirty (bordering on filthy), but a decent spike filter will at least protect you from over-voltage. It will not, however, cure the frequency and AC voltage regulation issues though. I've measured my GMC 750 watt unit and it wandered from 55 to 65 hertz and 180 to 270V AC. A pretty wild swing!

Nevertheless, I use it to run chargers and stuff without problem. I wouldn't run anything sensitive of it, but rather use a decent pure sine wave inverter off a good large battery.

Having said that - my only other advice is to throw out the spark plug that came with it and buy yourself an equivalent NGK. You'd be amazed at the difference that can make. Mine starts first time, every time, and has now clocked (logged) over 1,500 hours on our farm. Not bad for $99 at the Bunster. Make sure that you run it dry to turn it off - don't leave 2-stroke in the carby for any period of time. Turn off the tap and let it go until it stops.

[rmcpb]

If the power is so dirty why not use the generator to charge a battery which is hooked up to the scope a bit like a UPS?

[Omaroo]

That's precisely what we do Rob. That's where I was going, but didn't actually get there. :doh: It runs a charger for us most of the time. :thumbsup:

[montewilson]

Actually I bought a Honda 2000i and it is just amazing. Funny thing, the model number and the price are very similar but it has been well worth it.

The gen is quiet and has an inverter so the wave form is pure. The engine will rev down and up depending on the load so it uses less fuel and makes less noise too.

Still with a bit of patience and creative engineering the sub $100 gens can be a useful tool.

With all my stuff when I am at Ilford (ASNSW) I only have a constant usage of 475w. About 1/4 the max of the generator

That is 2 x TV's, 1 x 21" Monitor, 1 x desktop, 1 x STL11000m, 1 x STV, 2 x dew heaters, in house lights, EM200 mount fast slewing in both axies.

[Arthur Alchin]

As I mentioned in the first post I have a DSE purchased filter attached to the GMC generator. I mainly drive a Laptop as well as charge he power supply for the scope

The filter is CREST "X Stream Pro Powerguard" it has
* Programmable power-up delay
* Power fault condition indicators
*Active intelligent voltage sensing circuit
*cascade multistage filtering
*over and under voltage protection.

Any thoughts on the subject

Arthur

[Arthur Alchin]

As I mentioned in the first post I have a DSE purchased filter attached to the GMC generator. I mainly drive a Laptop as well as charge he power supply for the scope

The filter is CREST "X Stream Pro Powerguard" it has
* Programmable power-up delay
* Power fault condition indicators
* Active intelligent voltage sensing circuit
* cascade multistage filtering
* over and under voltage protection.

Any thoughts on the subject

Arthur

[montewilson]

Sounds good - it won't hurt to use it. Of course it can't fix frequency issues but for spikes it should be a help.