Howdy y'all.
My Garmin Nuvi GPS was caught in a heavy rainstorm several weeks ago.
I opened it to dry everything for 24h atop an oil heater (low heat).
All GPS functions still work, except the small loudspeaker, which is now barely audible.
I think it's the speaker, as I plugged a temporary mono patch-cord into my soundcard's line-in, touched sig/gnd wires across the speaker.
The GPS voice spoke loudly through PC-connected amplifier setup.
Speaker's DC resistance in-circuit, with GPS off, is 5R3.
I don't know therefore if this is 4 ohm or 6 ohm standard, or if i'm also reading parallel R of output stage.
No idea of wattage, as voice-coil screen-print is gone, if it was there at all.
May have been wiped off when I was pre-wiping and 'patting' dry with a bath-towel.
Soldering safe?
As I noticed the board is packed with SMD components, including several IC's and transistors, my concern is that my electric Soldering iron could blow CMOS etc.
Ideally, I would like to add a 'line-out' from the speaker's PCB solder-pads, maybe even remove the speaker from the unit.
If I loosely bunched a handful of aluminium foil, pressed as a grounding pad over entire board (battery removed), would this protect against ESD while soldering?
Loading Line:
As for load to a line-in socket, (Sony Front-End CD/Car Radio), I considered trying a temporary series 1K0 preset, gradually reduced until volume is sufficient.
Would a speaker-to-line-in conversion also need a series audio cap, for normalizing bias?
Inductive coupling to mini loudspeaker VC?
The speaker is a small, flat design, with voice-coil/magnet housing surrounded by the diaphragm 'cage', which is slotted metal, viewed from back.
After measuring the not-so-loudspeaker dimensions, I planar-wound a flat coil of hair-fine enamelled copper onto cardstock ring, n about 80T close-wound.
This flat planar coil was stuck to rear of cage, encircling center VC housing, litz-wired to RCA socket at back of unit.
The DC R is 5.3 - 5.4 ohms.
Poorly coupled?
No audio output, seriesed 11 ohm 1/8W resistor (16.3-16.4R) to avoid overloading my PC's soundcard mic in and line in.
The only audio heard is occasional (antenna output?) pulses like cellphone interference.
I guess the VC is helically wound, screened by metal 'faraday-cage' of speaker, and my creation is planar, perpindicular to VC?
Speaker specs?
I have several old half-stripped headphones, some with speakers that may fit in GPS.
These vary from 8R through 32R to around 64R.
Does anybody have specs for the Garmin Nuvi loudspeaker?
Nothing so far via web searches.
Our local RS keeps a range of drivers, so I could renew with same rating once known.
Thanks, Clive.
My Garmin Nuvi GPS was caught in a heavy rainstorm several weeks ago.
I opened it to dry everything for 24h atop an oil heater (low heat).
All GPS functions still work, except the small loudspeaker, which is now barely audible.
I think it's the speaker, as I plugged a temporary mono patch-cord into my soundcard's line-in, touched sig/gnd wires across the speaker.
The GPS voice spoke loudly through PC-connected amplifier setup.
Speaker's DC resistance in-circuit, with GPS off, is 5R3.
I don't know therefore if this is 4 ohm or 6 ohm standard, or if i'm also reading parallel R of output stage.
No idea of wattage, as voice-coil screen-print is gone, if it was there at all.
May have been wiped off when I was pre-wiping and 'patting' dry with a bath-towel.
Soldering safe?
As I noticed the board is packed with SMD components, including several IC's and transistors, my concern is that my electric Soldering iron could blow CMOS etc.
Ideally, I would like to add a 'line-out' from the speaker's PCB solder-pads, maybe even remove the speaker from the unit.
If I loosely bunched a handful of aluminium foil, pressed as a grounding pad over entire board (battery removed), would this protect against ESD while soldering?
Loading Line:
As for load to a line-in socket, (Sony Front-End CD/Car Radio), I considered trying a temporary series 1K0 preset, gradually reduced until volume is sufficient.
Would a speaker-to-line-in conversion also need a series audio cap, for normalizing bias?
Inductive coupling to mini loudspeaker VC?
The speaker is a small, flat design, with voice-coil/magnet housing surrounded by the diaphragm 'cage', which is slotted metal, viewed from back.
After measuring the not-so-loudspeaker dimensions, I planar-wound a flat coil of hair-fine enamelled copper onto cardstock ring, n about 80T close-wound.
This flat planar coil was stuck to rear of cage, encircling center VC housing, litz-wired to RCA socket at back of unit.
The DC R is 5.3 - 5.4 ohms.
Poorly coupled?
No audio output, seriesed 11 ohm 1/8W resistor (16.3-16.4R) to avoid overloading my PC's soundcard mic in and line in.
The only audio heard is occasional (antenna output?) pulses like cellphone interference.
I guess the VC is helically wound, screened by metal 'faraday-cage' of speaker, and my creation is planar, perpindicular to VC?
Speaker specs?
I have several old half-stripped headphones, some with speakers that may fit in GPS.
These vary from 8R through 32R to around 64R.
Does anybody have specs for the Garmin Nuvi loudspeaker?
Nothing so far via web searches.
Our local RS keeps a range of drivers, so I could renew with same rating once known.
Thanks, Clive.
