Spent a bit of time troubleshooting mom's adjustable hospital bed. It raises and lowers
head and legs independantly. It wasn't adjusting head and swapping the motor connections
with the leg motor had me thinking that the control board was bad.

Well, I took the control board home, probed and traced things and couldn't find a problem.

Uncle called and said I should come over and we would both noodle it out. I know he just
wanted adult company. He was watching kids at the time.

I expected a circuit that was powering one of two field windings at a time for up and
down. I saw power on both field connections all the time in respect to neutral. After a
while, I realized that there is a RC snubbing network across the contacts and my high
impedance DVM sees full voltage when a real load would see very little.

So I rig up a test light using one of his kids bed lamps. I'm getting flickers out of it
when I touch the connections. I can get full illumination also when I operate the remote
control that operates this thing. Kids light has some new technology bulb in it. Okay.
Lets put a real load on it, uncle finds a 150W incandescent light bulb to put in the lamp
(suck that Waxman). Now I don't have flickering checking the two fields again in respect
to neutral, just a solid on and off when I operate the remote control.

Damn, nothing seems wrong.

We put the controller back into the bed, the head raises but now the foot doesn't. Argh,
power cord was draped across a limit switch the lead screw can hit at one limit. Move the
cord, all works right. I hate this. I didn't fix it, it was broke and I didn't fix it
but it is working.

What is there to learn out of this? Well for one thing, a good old test light still has a
place in this world. Keep that in mind when troubleshooting power control in your
machines.

Wes
--

The only thing Obama has fixed is Carter's reputation.

Wes wrote:
Spent a bit of time troubleshooting mom's adjustable hospital bed. It raises and lowers
head and legs independantly. It wasn't adjusting head and swapping the motor connections
with the leg motor had me thinking that the control board was bad.

Well, I took the control board home, probed and traced things and couldn't find a problem.

Uncle called and said I should come over and we would both noodle it out. I know he just
wanted adult company. He was watching kids at the time.

I expected a circuit that was powering one of two field windings at a time for up and
down. I saw power on both field connections all the time in respect to neutral. After a
while, I realized that there is a RC snubbing network across the contacts and my high
impedance DVM sees full voltage when a real load would see very little.

So I rig up a test light using one of his kids bed lamps. I'm getting flickers out of it
when I touch the connections. I can get full illumination also when I operate the remote
control that operates this thing. Kids light has some new technology bulb in it. Okay.
Lets put a real load on it, uncle finds a 150W incandescent light bulb to put in the lamp
(suck that Waxman). Now I don't have flickering checking the two fields again in respect
to neutral, just a solid on and off when I operate the remote control.

Damn, nothing seems wrong.

We put the controller back into the bed, the head raises but now the foot doesn't. Argh,
power cord was draped across a limit switch the lead screw can hit at one limit. Move the
cord, all works right. I hate this. I didn't fix it, it was broke and I didn't fix it
but it is working.

What is there to learn out of this? Well for one thing, a good old test light still has a
place in this world. Keep that in mind when troubleshooting power control in your
machines.

Eyeball the thing before taking it apart. There's
been many times I wished I'd remembered.

On Dec 28, 8:33*pm, Wes wrote:
Spent a bit of time troubleshooting mom's adjustable hospital bed. *It raises and lowers
head and legs independantly. *It wasn't adjusting head and swapping the motor connections
with the leg motor had me thinking that the control board was bad.

Well, I took the control board home, probed and traced things and couldn't find a problem.

Uncle called and said I should come over and we would both noodle it out. *I know he just
wanted adult company. *He was watching kids at the time. *

I expected a circuit that *was powering one of two field windings at a time for up and
down. *I saw power on both field connections all the time in respect to neutral. After a
while, I realized that there is a RC snubbing network across the contacts and my high
impedance DVM sees full voltage when a real load would see very little.

So I rig up a test light using one of his kids bed lamps. *I'm getting flickers out of it
when I touch the connections. *I can get full illumination also when I operate the remote
control that operates this thing. *Kids light has some new technology bulb in it. *Okay.
Lets put a real load on it, uncle finds a 150W incandescent light bulb to put in the lamp
(suck that Waxman). * Now I don't have flickering checking the two fields again in respect
to neutral, just a solid on and off when I operate the remote control.

Damn, nothing seems wrong. *

We put the controller back into the bed, the head raises but now the foot doesn't. *Argh,
power cord was draped across a limit switch the lead screw can hit at one limit. *Move the
cord, all works right. *I hate this. *I didn't fix it, it was broke and I didn't fix it
but it is working.

What is there to learn out of this? *Well for one thing, a good old test light still has a
place in this world. * Keep that in mind when troubleshooting *power control in your
machines.

Wes
--

The only thing Obama has fixed is Carter's reputation.

My friend's an elevator engineer. The repair crew couldn't figure out
an intermittent problem with an escalator and kept calling him at the
office. Finally he went down to the site shined a flashlight alongside
of the escalator and saw an unsecured cable hanging down bumping the
side of the escalator treads. Ten minutes to solve what two guys
couldn't find in four hours. Of course 25 years of experience might
have had something to do with it.
Karl

"Wes" wrote in message
...
Spent a bit of time troubleshooting mom's adjustable hospital bed. It
raises and lowers
head and legs independantly. It wasn't adjusting head and swapping the
motor connections
with the leg motor had me thinking that the control board was bad.

Well, I took the control board home, probed and traced things and couldn't
find a problem.

Uncle called and said I should come over and we would both noodle it out.
I know he just
wanted adult company. He was watching kids at the time.

I expected a circuit that was powering one of two field windings at a
time for up and
down. I saw power on both field connections all the time in respect to
neutral. After a
while, I realized that there is a RC snubbing network across the contacts
and my high
impedance DVM sees full voltage when a real load would see very little.

So I rig up a test light using one of his kids bed lamps. I'm getting
flickers out of it
when I touch the connections. I can get full illumination also when I
operate the remote
control that operates this thing. Kids light has some new technology bulb
in it. Okay.
Lets put a real load on it, uncle finds a 150W incandescent light bulb to
put in the lamp
(suck that Waxman). Now I don't have flickering checking the two fields
again in respect
to neutral, just a solid on and off when I operate the remote control.

Damn, nothing seems wrong.

We put the controller back into the bed, the head raises but now the foot
doesn't. Argh,
power cord was draped across a limit switch the lead screw can hit at one
limit. Move the
cord, all works right. I hate this. I didn't fix it, it was broke and I
didn't fix it
but it is working.

What is there to learn out of this? Well for one thing, a good old test
light still has a
place in this world. Keep that in mind when troubleshooting power
control in your
machines.

Wes
--

The only thing Obama has fixed is Carter's reputation.


Having had to repair hospital beds too many times, I found that the wire
connectors were often at fault. I often found bad connections and
corrosion. These beds are hostile environments in more ways than one.

"Wes" wrote in message
...
Spent a bit of time troubleshooting mom's adjustable hospital bed. It
raises and lowers
head and legs independantly. It wasn't adjusting head and swapping the
motor connections
with the leg motor had me thinking that the control board was bad.

Well, I took the control board home, probed and traced things and couldn't
find a problem.

Uncle called and said I should come over and we would both noodle it out.
I know he just
wanted adult company. He was watching kids at the time.

I expected a circuit that was powering one of two field windings at a
time for up and
down. I saw power on both field connections all the time in respect to
neutral. After a
while, I realized that there is a RC snubbing network across the contacts
and my high
impedance DVM sees full voltage when a real load would see very little.

So I rig up a test light using one of his kids bed lamps. I'm getting
flickers out of it
when I touch the connections. I can get full illumination also when I
operate the remote
control that operates this thing. Kids light has some new technology bulb
in it. Okay.
Lets put a real load on it, uncle finds a 150W incandescent light bulb to
put in the lamp
(suck that Waxman). Now I don't have flickering checking the two fields
again in respect
to neutral, just a solid on and off when I operate the remote control.

Damn, nothing seems wrong.

We put the controller back into the bed, the head raises but now the foot
doesn't. Argh,
power cord was draped across a limit switch the lead screw can hit at one
limit. Move the
cord, all works right. I hate this. I didn't fix it, it was broke and I
didn't fix it
but it is working.

What is there to learn out of this? Well for one thing, a good old test
light still has a
place in this world. Keep that in mind when troubleshooting power
control in your
machines.

Wes

Darn. Sounds like you need one of them $400 diagnostic whitzits. Basically
the same thing, just colored lights and some dials. Oh, yeah, LCD digital
readout, too.

Would have saved you a lot of time.

Steve ;-)

"Jim Stewart" wrote

Eyeball the thing before taking it apart. There's
been many times I wished I'd remembered.

I have found those newfangled digital cameras work good, too. Of course, I
can always remember where things go, and how I took it apart, even weeks
later, but for those of you who have problems .............

Steve