If polarity were reversed on the battery supply to knot and depth meters, would this cause irrevocable damage, or is there a reset for these devices in general. Apparently the instruments will light up, but there are no readings/numbers in the displays. I'm not sure what make they are, I'll have to ask the guy if that makes a difference. The only other thing he told me was that his wife hooked the battery and solar charger up in reverse polarity for a minute or two until he realized what had happened.....
- Status
- Not open for further replies.
T
Tom s/v GAIA
D
Don Alexander
Idiot Diode
Adam, Many designers include what they call an "Idiot Diode" on the DC input side of their electronic devices. This is intended to protect the instrument should anyone connect it with reverse polarity - hence its name. There are two ways they do this. The first is to fit an internal diode in series with the instrument. This prevents the reverse polarity from geting through to the innards. Another way is to put the diode right across the 12 volt input so that it blows the in line fuse. Both ways are very inexpensive to carry out and many wise designers do this. Either, way correcting the polarity (and resetting the breaker) should bring the unit back to life. Your system appears not to have blown a fuse or tripped a breaker because the internal lights work, and as the instruments do not function then it looks as if they may well have died. May I suggest removing them and asking a local electronics shop to check them out. Next time, before buying, enquire if they are idiot protected - no slur intended to your best beloved as these things can easily happen.
Adam, Many designers include what they call an "Idiot Diode" on the DC input side of their electronic devices. This is intended to protect the instrument should anyone connect it with reverse polarity - hence its name. There are two ways they do this. The first is to fit an internal diode in series with the instrument. This prevents the reverse polarity from geting through to the innards. Another way is to put the diode right across the 12 volt input so that it blows the in line fuse. Both ways are very inexpensive to carry out and many wise designers do this. Either, way correcting the polarity (and resetting the breaker) should bring the unit back to life. Your system appears not to have blown a fuse or tripped a breaker because the internal lights work, and as the instruments do not function then it looks as if they may well have died. May I suggest removing them and asking a local electronics shop to check them out. Next time, before buying, enquire if they are idiot protected - no slur intended to your best beloved as these things can easily happen.
B
Brian R Clare
Maybe lights are on seperate circuit
Its possiable that the lighting and instument power are on two seperate circuits as is the case with my 272LE.Therefore the idiot diode inside the units may have taken out the line fuse or breaker to the instrument and the lighting (not polarity sensitive) is still working from its source. Check the back of the units do they have two 12V inputs? Brian
Its possiable that the lighting and instument power are on two seperate circuits as is the case with my 272LE.Therefore the idiot diode inside the units may have taken out the line fuse or breaker to the instrument and the lighting (not polarity sensitive) is still working from its source. Check the back of the units do they have two 12V inputs? Brian
G
Gord May
Light On
1. See Don's re 'idiot diodes' 2. The light may be an incandescent type lamp, which is not polarity sensitive. 3. The LED's (numbers), & processor are polarized. Do I understand correctly; that the unit lights up but does not display AFTER re-connecting properly? Check for an internal fuse. Regards, Gord
1. See Don's re 'idiot diodes' 2. The light may be an incandescent type lamp, which is not polarity sensitive. 3. The LED's (numbers), & processor are polarized. Do I understand correctly; that the unit lights up but does not display AFTER re-connecting properly? Check for an internal fuse. Regards, Gord
A
Adam
Thanks for the suggestions, but...
Don--I'm not married..... This happened to a guy on the next mooring from my boat, I heard the cursing and saw the head-shaking as they were headed past my boat at the end of the day. Anyhow, I'll pass along the info. But from what he tells me, the guages are getting illuminated, but no numbers show up at all on the guages. Supposing there is an internal fuse in the instruments, how would one go about identifying that? My electrical experience is OK, but his doesn't appear to be....
Don--I'm not married..... This happened to a guy on the next mooring from my boat, I heard the cursing and saw the head-shaking as they were headed past my boat at the end of the day. Anyhow, I'll pass along the info. But from what he tells me, the guages are getting illuminated, but no numbers show up at all on the guages. Supposing there is an internal fuse in the instruments, how would one go about identifying that? My electrical experience is OK, but his doesn't appear to be....
T
Tom s/v GAIA
Fuses arn't bothered by polarity.
And if there was a diode (spell) in place it would have blocked the power and saved the units. Tom s/v GAIA
And if there was a diode (spell) in place it would have blocked the power and saved the units. Tom s/v GAIA
G
Gord May
Lights on - no one home
Tom is correct, fuses aren't polarized, and a polarity blocking diode should have protected the LED & Processor. Often, a fuse can blow (for no apparent reason) when equipment is first connected (reconnected) - hence the internal fuse check. Because the unit lights up, I don't really suspect a blown internal fuse, uunless there are multiple CPD's inside (superior equipment often does this). Unfortunately, it doesn't sound as tho' the owner will be competant to check much beyond this point. Gord
Tom is correct, fuses aren't polarized, and a polarity blocking diode should have protected the LED & Processor. Often, a fuse can blow (for no apparent reason) when equipment is first connected (reconnected) - hence the internal fuse check. Because the unit lights up, I don't really suspect a blown internal fuse, uunless there are multiple CPD's inside (superior equipment often does this). Unfortunately, it doesn't sound as tho' the owner will be competant to check much beyond this point. Gord
- Status
- Not open for further replies.