DC to DC Multi-Purpose Voltage Converter $14.98

[wojtek]

another question- are there any converters available that would take around 20W-30W out?

[Lyen]

Hi Woktek,

Thanks for your interest in the DC converters. I think the converter is ready 20-30W capable according to the specification. For example, power is voltage multiply by current. So for instance, 10v at 3A is already 30 watts.

Regards,
Lyen

another question- are there any converters available that would take around 20W-30W out?

[mikebikerad]

Recieved mine. Works awesome and powers up my magic shine nicely. Running it on 48 volt battery.

[NeilP]

Well after a couple of PM's with Lyen, and talking about my 84 volt pack...my requirements could not be met with these convertors...so I went down the local dump and came back with about a dozen small mains power supplies form things like LCD monitors, video cameras, portable speakers, printers etc etc.

all ranging from 100 to 240 volt input and various outputs, from 5 volt to 18 volt. Well sticking 84 volt DC in to them, and they pretty much all worked.. Often taking a few moments longer to power up than if feeding them with 240v AC. SO now I have a variety of small SMPSu's all usable with 84 volt in.
So my problem solved, all with PSU's from the dump

[ambroseliao]

I'm wondering how clean (ripple) the DC voltages are from those small units? Do you have a oscilloscope by any chance?

Ambrose

[NeilP]

Possibly. At least I can probably get access to one

I only plan to power small halogen or led light units off them, so should be ok for that. I recently picked up a box of 20 or more 12 v 20 and 35W mini spotlights.... Not sure what they are called, but they are the same type as my 6v 10w Catseye bike headlamp...so as long as I do not melt the housing , should be ok

Will see if I can get a scope across the outputs

Neil

[hillzofvalp]

send me a light

[NeilP]

They are not complete units, just the bulb . Only have one of the housings

[ecodean]

Hi Lyen. Could 4 of these be wired in parallel to make a 12a supply?

[NeilP]

Sorry Ambrose, still not chance of getting to a scope.

I have tried running my 7.2 volt lights off a 12 v unit and they work fine. I did not just stick 1 v straight up them...I mailed the manufacturer, andt ehy mailed me back saying the front end voltage control circuitry was OK to up to 12 v..Di Notte lighting..make great lights

[thenate1]

Anyway to get more AMPs flowing through these? I want to use one to power some heated grips and the manufactures emailed me back saying:

"12 volts DC will be fine to run the grips. They will draw about 3.5 amps or 44 watts per pair as they come up to the set temperature. After they have reached the set temperature (when the blue lights on each grip stop pulsating) the amp draw can vary between 0 and 3.5 amps, depending on conditions."

[oldpiper]

Anyway to get more AMPs flowing through these? I want to use one to power some heated grips and the manufactures emailed me back saying:

"12 volts DC will be fine to run the grips. They will draw about 3.5 amps or 44 watts per pair as they come up to the set temperature. After they have reached the set temperature (when the blue lights on each grip stop pulsating) the amp draw can vary between 0 and 3.5 amps, depending on conditions."

If you just want a standard 12V, why not get one of the many 48V-12V converters available on eBay or such? Lyen's converters are about the only ones I've seen which you could tweak for nonstandard voltages, but there are several to choose from for conversion to 24V, 12V, 5V, 3.3V, etc.

Cameron

[NeilP]

Or just do what I did and find an old Mains PSU that runs 12volt. If it has an input showing 100-240V AC, chances are it will work...not if it is a big old fashoned heavy transformer type, it needs to be a switched mode type.

I found a load, in the range 3-6 amps...the sort used to power LCD PC monitors are good

[Lyen]

Hi Ecodean,

Thanks for your interest in the DC to DC multi-purpose voltage converter. Yes, you may connect four converters in parallel as a 12A power supply.

Regards,
Lyen

Hi Lyen. Could 4 of these be wired in parallel to make a 12a supply?

[ChinaPhil]

I use an iPhone 4 for navigation and have been trying to power / charge it with one of these converters set at 5V and powering a USB charging cable - cannot get it to work, any suggestions?

Phil

[Lyen]

I use an iPhone 4 for navigation and have been trying to power / charge it with one of these converters set at 5V and powering a USB charging cable - cannot get it to work, any suggestions?

Phil

Hi Phil,

The iPhone 4 needs to sense voltage on the USB data pins. Its wall charger definitely outputs 2V & 2.7V on the two USB data lines, as well as the 5V on the USB Pwr pin.

If you have some electronics experience, follow the instructions below to construct your own charging adapter cable.
If you never soldered before, then don’t try. If you connect things wrong there is the potential risk of damaging the phone.
As usual, if you do make your own cable, you do it entirely at your own risk. If your phone dies, do not blame me. Mine is working fine, so the procedure does work if done properly.

Instructions:
READ ALL STEPS BEFORE STARTING WORK!
The USB has 4 wires:
Red-5V, White-Data, Green-Data, Black-Gnd.
They are numbered Pin1 to Pin4, in the same order, ie Red =Pin1.
1. Cut the USB EXTENSION lead, trim both pieces to a shorter size, but make sure you leave enough length to work with !
2. Cut off the foil-shielding on both pieces, twist the braided wire shielding into a single “wire” on each piece.
3. On the female piece of the lead solder resistors as follows:
Pin1—R1—Pin2—R2—Pin3—R3—Pin4—Shield
R1=2K2; R2=680; R3=2K2
4. Trim resistor legs as short as possible. Make sure you put some insulating tape between all the exposed bits of wire and resistor legs. You want to pack the resistors as tight as you can, and you do not want any metal bits touching!
5. On the male end of the lead, cut off the white and green wires; you DO NOT want to connect them to anything! If they were connected it would feed power back to the car adapter, which could conceivably have those pins grounded as they’re usually not used (hence the iPhone 4 charging problem).
Even worse, you might one day accidentally plug this new DIY adapter cable into a USB port on your PC, and it may take offense at having power coming in on the data lines.
So cut the green and white wires on the male end.
6. Cut a piece of large-diameter heat-shrink and slide it over the male piece of the lead. It should be long enough to later cover the area where the resistors are. Hence the male end of the lead needs to be at least as long as the length of heat-shrink you need!
7. Join the two pieces of lead by soldering the male red wire to the female red, male black to female black, the shields to the blacks.
8. Carefully compact all the resistors together, ensuring there is insulation between adjacent metal parts, and that nothing comes lose. You might need to think about how you want to pack the resistors BEFORE YOU SOLDER!
Then slide the heat-shrink over the resistor assembly until it overlaps the untouched part of the the USB cable on both sides of the resistor assembly.
Heat up heat-shrink to make it grip.
* If the assembly is bigger than the heat-shrink you chose, remove heat-shrink and tightly wrap the entire cable with electrical tape instead. Done!
9. WAIT! DO NOT CONNECT iPhone, yet!!!!
10. Connect your new adapter cable to the DC-DC converter.
With a multimeter (and thin probes, or bit of stiff wire soldered to the probe tip) measure the voltages you get on the female end of your new adapter cable.
Put the Gnd-Probe on the plug shield, and be extremely careful with the other probe not to touch both the shield and a pin at the same time.
You should have ~5V on Pin1, ~2.8V Pin2, ~2V Pin3, 0V Pin4.
If you do, Congratulations, you now have a USB adaptor cable that will turn any plain USB voltage adaptor into an iPhone 4 charger.
If you have no voltage, you might have forgotten to solder the shield to the black. Put Gnd-probe on Gnd-Pin4, then measure all other pins and shield. If the pins measure ok, and the shield is still 0V, you are probably ok too.
All other results, and you need to re-do your cable!
11. IF YOUR CABLE MEASURES OK, at your own risk (!) you can now connect your iPhone to the adapter cable, and then into the DC-DC converter. It should now charge.
Note: Apple states that the iPhone should only be connected to authorised chargers,etc. Using the DIY adapter cable could potentially void your warranty.

Please be careful though :
When cutting an USB extention cable : Do not rely on the wire colours !!!
Mine had red colour connected to pin2, black wire connected to Pin 3, green (5V) connected to pin 1 and white connected to Pin4 (GND)
Measure twice !

Regards,
Lyen

[wojtek]

WOW Lyen, that is impressive!!!

[ChinaPhil]

I use an iPhone 4 for navigation and have been trying to power / charge it with one of these converters set at 5V and powering a USB charging cable - cannot get it to work, any suggestions?

Phil

Hi Phil,

The iPhone 4 needs to sense voltage on the USB data pins. Its wall charger definitely outputs 2V & 2.7V on the two USB data lines, as well as the 5V on the USB Pwr pin.

If you have some electronics experience, follow the instructions below to construct your own charging adapter cable.
If you never soldered before, then don’t try. If you connect things wrong there is the potential risk of damaging the phone.
As usual, if you do make your own cable, you do it entirely at your own risk. If your phone dies, do not blame me. Mine is working fine, so the procedure does work if done properly.

Instructions:
READ ALL STEPS BEFORE STARTING WORK!
The USB has 4 wires:
Red-5V, White-Data, Green-Data, Black-Gnd.
They are numbered Pin1 to Pin4, in the same order, ie Red =Pin1.
1. Cut the USB EXTENSION lead, trim both pieces to a shorter size, but make sure you leave enough length to work with !
2. Cut off the foil-shielding on both pieces, twist the braided wire shielding into a single “wire” on each piece.
3. On the female piece of the lead solder resistors as follows:
Pin1—R1—Pin2—R2—Pin3—R3—Pin4—Shield
R1=2K2; R2=680; R3=2K2
4. Trim resistor legs as short as possible. Make sure you put some insulating tape between all the exposed bits of wire and resistor legs. You want to pack the resistors as tight as you can, and you do not want any metal bits touching!
5. On the male end of the lead, cut off the white and green wires; you DO NOT want to connect them to anything! If they were connected it would feed power back to the car adapter, which could conceivably have those pins grounded as they’re usually not used (hence the iPhone 4 charging problem).
Even worse, you might one day accidentally plug this new DIY adapter cable into a USB port on your PC, and it may take offense at having power coming in on the data lines.
So cut the green and white wires on the male end.
6. Cut a piece of large-diameter heat-shrink and slide it over the male piece of the lead. It should be long enough to later cover the area where the resistors are. Hence the male end of the lead needs to be at least as long as the length of heat-shrink you need!
7. Join the two pieces of lead by soldering the male red wire to the female red, male black to female black, the shields to the blacks.
8. Carefully compact all the resistors together, ensuring there is insulation between adjacent metal parts, and that nothing comes lose. You might need to think about how you want to pack the resistors BEFORE YOU SOLDER!
Then slide the heat-shrink over the resistor assembly until it overlaps the untouched part of the the USB cable on both sides of the resistor assembly.
Heat up heat-shrink to make it grip.
* If the assembly is bigger than the heat-shrink you chose, remove heat-shrink and tightly wrap the entire cable with electrical tape instead. Done!
9. WAIT! DO NOT CONNECT iPhone, yet!!!!
10. Connect your new adapter cable to a car USB adapter.
With a multimeter (and thin probes, or bit of stiff wire soldered to the probe tip) measure the voltages you get on the female end of your new adapter cable.
Put the Gnd-Probe on the plug shield, and be extremely careful with the other probe not to touch both the shield and a pin at the same time.
You should have ~5V on Pin1, ~2.8V Pin2, ~2V Pin3, 0V Pin4.
If you do, Congratulations, you now have a USB adaptor cable that will turn any plain USB voltage adaptor into an iPhone 4 charger.
If you have no voltage, you might have forgotten to solder the shield to the black. Put Gnd-probe on Gnd-Pin4, then measure all other pins and shield. If the pins measure ok, and the shield is still 0V, you are probably ok too.
All other results, and you need to re-do your cable!
11. IF YOUR CABLE MEASURES OK, at your own risk (!) you can now connect your iPhone to the adapter cable, and then into the car adapter. It should now charge.
Note: Apple states that the iPhone should only be connected to authorised chargers,etc. Using the DIY adapter cable could potentially void your warranty.

Please be careful though :
When cutting an USB extention cable : Do not rely on the wire colours !!!
Mine had red colour connected to pin2, black wire connected to Pin 3, green (5V) connected to pin 1 and white connected to Pin4 (GND)
Measure twice !

Regards,
Lyen

Lyen, thank you. I will give this a go after I have been resistor shopping. Hope that your instructions help others.

Phil

[NeilP]

I'm wondering how clean (ripple) the DC voltages are from those small units? Do you have a oscilloscope by any chance?

Ambrose

I did think about going down to a mates to try a scope on the output of the small SMPU's that I got from th dump and ran at 84 v or less from my bikes pack,and have not got round to it yet, but it has occurred to me that , even if he did, the results would be meaningless to you unless you had the exact same model power supply.

As far as I understand, since these are switched mode units, the input is going to have absolutely no bearing on the smoothness of the output, this is solely going to be a factor of the design of that particular supply, so any results I may find from the SMPSU's I have would be different for any supplies you find.

I may still go ahead and try and see the chap, and give it a try, just out of curiosity now, but I do not thing it will produce any useful information.

As for going below 84 volts...not sure what voltage I initially tried this out at, when I first tried running one of them off DC, but it would not have been a fully charged pack in any case...it would have at least been down to about 75 v by the time I had got to the farm workshop, where I do all my bike building

Neil

[ChinaPhil]

Confirming that Lyen's iPhone charging instructions work, thank you once again.

Phil

[jonathanm]

Want one of these to hook up my android phone for using speedict ebike.....payment sent!

[ohzee]

bought one - 2nd item I have bought from Lyen and his shipping is IMPRESSIVE to say the least.

Placing a 2nd order now.

[geoff57]

Hi
Iphone charger.
For those that worry about getting the resistors correct there is an alternative, iphone car chargers with built in cables to a iphone for not a lot of cash, if opened up you will find that most if not all only have 2 wires coming down the cable, the resistor network is hardwired into the connector.this means that there is an alternative charger that requires no skill in getting resistors in the right order.

1: prepare the power in to the DC to DC converter in the same way as in the previous instructions. Connect Positive (60V to 8V) and ground to ground, if using a battery then fit it between the battery and V IN + if fitted on the V O + side then the DC to DC converter will be draining the battery all the time and if lithium with no LVC protection the battery could well end up discharged beyond repair.
2: you now have the Converter connected to a power supply (battery or mains PSU), take a multimeter put it over V O + and V O - turn the screw pot untill the meter reads 5.1V. Now disconnect the power supply and get ready to do the rest of the soldering.
3: check which is the positive and negative wire in the charging cable you have, (if there are more than 2 wires the cable is not a charging cable but a data cable) most probably the wires will be Red and Black but don't rely on the colors.
4: once identified solder the lead to the V O+ and V O - positive and negative respectively.
5: the output wires are probably very thin and only PVC insulated, for the wires strength and insulation cover the 2 wires with heat shrink to where the wires are striped, on the connection either use heat shrink if it is possable or if on a circuit board use silicone or epoxy glue don't use heat melt glue as when in use the converter gets hot.
6: put the whole thing into a small case plastic or metal, the heat from the converter will not be enough to melt a plastic one( it has never melted mine anyway ) you just have an input wire an output wire and an optional switch on the box.

I made my charging unit soon after this thread started so that I could charge my iPad from a LiPo battery pack the converter gets very hot but I have had no problems when charging my iphone it charges like its on steroids.

This build is in effect the same as was described above it just avoids working out where to put the resistors, infant the resistors are not needed.

Geoff

[hillzofvalp]

For those of u who have a 12-24V auxiliary supply, many of the car USB ports regulate this range. I got mine for free at a job fair booth, but I'm sure you could get one for less than $5. It's only 700mA though... I can't remember what the highest the iPhone can take

[nonlineartom]

Personally I just have the DCDC converter running at 12V and then use a cigarette lighter USB charger to charge the phone up. I know it's effectively 2 DCDC converters but it gives the iPhone power it's happy about and doesn't risk damaging the phone. I'm guessing it uses some kind of regulator built it. Doesn't add much bulk