64 October 2017
>>>YOUR ELECTRONICS QUESTIONS ANSWERED HERE BY N&V READERS
Since then, I have tried the same
monitor several more times with the
same supply, and also used my car’s
battery, my lawn tractor’s battery, and
even purchased and tried a 12 VDC at
1A supply all with the same results.
What is the power requirement
for such mini monitors? I don’t want
to burn any of them out using the trial
and error method.
#1 These monitors are typically
used for backup cameras in vehicles,
which means they likely use 12 VDC.
You didn’t mention if you had tried to
feed a video signal into them when
you applied power.
Backup cameras are usually wired
to the reverse light of the vehicle, so
that when you shift into reverse, the
camera is powered and sends a signal
to the monitor. The monitor then
automatically turns on.
So, perhaps this might be the
issue — that the monitor needs a
video signal to turn on.
#2 This monitor looks like one I
have used in the past and they need
a video signal input before they will
power up. The 12V 500 mA power
supply should be fine.
[#7171 - July 2017]
There has been quite a bit of news
lately about so-called “ransomware.”
Can someone explain how it works
and is there a fool-proof way to keep
my machines (and those of my family)
Ransomware is malware that
encrypts your drive so that you
cannot access it without buying a key
(password). About half the time, the
mark pays the money and doesn’t
get the key, or files are so damaged
the “key” is useless. Best thing to
guarantee safety from ransomware
(and other malicious malware):
Backup (or better, image) your
drive(s) as often as feasible and store
the image disconnected from the PC.
You can always revert to that image.
In addition, use anti-malware
software suites with good reputation,
such as Avira, Avast!, or Kaspersky.
Or, use an operating system less likely
to be attacked, such as Linux (though
Linux is not invulnerable, it has a far
lower incidence of malware).
[#7172 - July 2017]
I have an older model Hunter
SRC sprinkler controller that came
with my house. Recently, the unit has
been “resetting” to 12:00 am rather
than keeping time. The unit has a nine
volt battery that was reading 2.7V, so
I replaced the battery. Within a week,
the problem was back and the new
battery was also dead ( 3.1V).
Any ideas what could be killing
the batteries? I can’t find a schematic
for this unit.
No doubt an electrolytic cap
in the power supply has excessive
leakage. You could replace all
electrolytics, but the large one in the
power supply is most likely the culprit.