On Tue, 30 Jan 2018 02:37:12 +0000, alan_m wrote:

On 29/01/2018 22:00, T i m wrote:

I went for one of these as they generally seemed 'highly recommended'.

https://www.tooled-up.com/steinel-gl...melt-glue-gun/
prod/134729/



Looks identical to my Aldi/lidl gun which cost around £5

It looks similar to my Marksman Tools gun which I suspect may have been
an Aldi/Liddle purchase a few years ago (but possibly purchased from
another emporium).

This one has a very peculiar power consumption characteristic which
seems to be common to all hot glue guns. I've also got a very small "Bond
iT" 110 to 240v 10W gun, tucked away in a drawer unused for lack of the
5mm dia glue sticks it takes. This swiftly ramps up to just over 100W in
the first second of being plugged in (actually bangs into the end stop on
the 100v by 1A scale of my analogue wattmeter) before more leisurely
dropping back to 20 watts or so after 10 or 15 seconds, presumably
settling down to its 10W idling state if given another minute or so. I
think this tiny glue gun was purchased in a 99 pence shop about ten years
ago.

The Marksman gun takes 11mm dia gluesticks and I've just spotted its
rating label which states ac 230v 50Hz FL-158 b 40W. Presumably the FL-158
b is the model number and the 40W must be its active consumption.

According to my watt meter, it takes an initial peak power of some 350W
[1] before throttling back to 100W a few seconds later, eventually
settling down to 35W after about a minute or so of warming up.

The specification data shown on that page you linked to is rather
interesting in that it neatly describes this rather peculiar behaviour of
power consumption which would be rather tricky to to verify with an
ordinary plug in digital energy consumption monitor (aka, digital watt
meter), it needs a genuinely analogue wattmeter to verify this behaviour
and those, as I learnt just a few short years ago, are basically as rare
as Rocking Horse **** or hen's teeth[2].

[1] It hadn't fully cooled down from my initial test when I'd grossly
underestimated what the peak demand was likely to be and chosen the 200v
by 1A setting for the first test. I'm waiting for it to more fully cool
down before repeating the test on the 500W scale. Whilst I'm waiting,
I'll write note [2]... Well, it peaked to 65 on the scale which works out
to a 325W peak on the 100v by 5A settings. It wasn't quite stone cold but
I rather doubt it would have peaked beyond the 350W mark even if had been.

I guess the "PTC" mentioned in the "Features & Benfits section on that
web page is the key to this very common behaviour of hot glue guns
(presumably a reference to "Positive Temperature Coefficient").

[2] I had a very strong inkling that the Metrawatt analogue watt meter I
had been eyeing up at a radio ham rally some 30 odd years ago was quite
likely my one and only chance of getting hold of such a test instrument
at an affordable price. Even so, for the time, the 35 quid asking price
seemed a rather high one for a 2nd hand test meter but, as I surmised, it
was well worth a punt to get my hands on what I knew to be a rarity in
test meters - I just didn't appreciate exactly how rare a piece of test
kit it actually was until I researched the availability and pricing of
such test gear many years later via the internet (about 6 to 7 years ago
now).

Contrary to my expectations, it has proven to be a remarkably useful
test tool in troubleshooting desktop computer faults, completely removing
the guesswork out of diagnosing the primary cause of boot failure issues
(dead PSU or MoBo?) as well as answering questions in regard of what a
piece of kit actually consumes compared to what's claimed on its rating
plate. It's also proved how dire the very first affordable plug in
digital 'watt meters' actually were as well as confirming the much better
accuracy of the more recent models of plug in energy consumption meters
from the Kill-A-Watt class period onwards.

You can take it from me that those 10 to 20 quid plug in energy
consumption monitors sold by Maplin can be trusted to be within a tenth
of a watt accuracy for typical wallwart powered kit and within +/- 3% for
heavier loads in the 100 to 3000 watt range. No need to thank me for this
useful piece of information but if you do, you're welcome. :-)

--
Johnny B Good