DC TO DC converter"Constant current"

[Moha99]

Hallo!

I recently bought the recom RCD-24-0.70 series hoping to have a constant current of 700mA and a adjustable voltage since it's clearly stated output voltage "2 - 35Volts/DC"

I have a problem with it... I'm not interested in using some LED'S I want to power some DC appliances under 500mA using this driver.

I bought this at a very expensive price since I'm in a rush and needed it to be shipped quickly could you tell me how can I adjust the voltage? I followed the diagram supplied from the company and I could not increase the voltage I really don't know why came here hoping someone could shed some light into this problem.
Some read the datasheed stating its a "STEPDOWN" converter I doubt that... And yea I have a input of 6Volts DC! The driver requires a minimum of 4.5 volt and a max to about 36 volts DC in.

Thanks!

Here's some info about the driver:
Digi-Key - 945-1123-ND (Manufacturer - RCD-24-0.70)

Datasheet:
**broken link removed**

 

[RetroTechie]

Welcome Moha99!

I have a problem with it... I'm not interested in using some LED'S I want to power some DC appliances under 500mA using this driver.

I bought this at a very expensive price since I'm in a rush and needed it to be shipped quickly could you tell me how can I adjust the voltage?

Don't count on it, a current source is a current source. So if you bought the 700mA version, it would simply try to produce whatever voltage is needed to obtain 700mA output current. And (since step-down) require a slightly higher input voltage to do that.

About the only way you could regulate a voltage with that, is add a circuit to drain/waste the exact amount of current to produce desired output voltage. Read: what you want to power with it, eats X mA @ Y volts, and you have a circuit in parallel that adjusts itself to eat exactly (700 - X) mA @ Y volts. Not saying that's impossible, but in practical terms: forget it.

I bought this at a very expensive price since I'm in a rush and needed it to be shipped quickly

There is a saying in my country: "haastige spoed is zelden goed". Which means something like: "running quickly is rarely a good thing". :wink:

 

[Moha99]

aah!!

Ok then what do you think of this one?
**broken link removed**

 

[RetroTechie]

Ok then what do you think of this one?
**broken link removed**

Doesn't look like what you might want...

I want to power some DC appliances under 500mA using this driver.

What are some typical voltage/current combinations for these devices? You need fixed voltages (1 converter for each device to power), or adjustable voltage (that you use for device A, then for device B, then for device C, etc) ? And: what do you intend to use as power source (AC, DC, voltage range) ? Do you want cheapest possible solution, or easiest-to-use option? Can you put together a circuit with regulator, cooling plate, capacitors, coil, whatever, or do you want a ready-made module?

 

[Moha99]

Doesn't look like what you might want...


What are some typical voltage/current combinations for these devices? You need fixed voltages (1 converter for each device to power), or adjustable voltage (that you use for device A, then for device B, then for device C, etc) ? And: what do you intend to use as power source (AC, DC, voltage range) ? Do you want cheapest possible solution, or easiest-to-use option? Can you put together a circuit with regulator, cooling plate, capacitors, coil, whatever, or do you want a ready-made module?

The power source is 6Volts Dc I'd like to convert it to 12 volts and up +.
To power up other Dc motors using less than 1AMP and 6 volts and 12 volts DC.
Simple brushless motors
Im thinking to get an adjustable step up converter.

And yes I want a ready model.

 

[RetroTechie]

Tracopower and Recom are known for their easy-to-use, compact, efficient and expensive DC-DC converter modules. For example I have a couple from TSR-1 series that are high-efficiency drop-in replacement for 7805 regulators. Up to 1A, no cooling plate necessary. But: around 7-8 Euro / piece...

But it looks like most need at least ~9V input, so you might be better off using an easy-to-find, cheap, step-up switching regulator IC like from LM25xx series, combined with a suitable coil. A bit more do-it-yourself, but IC's like these are pretty easy to use, just stick to sample application(s) found in datasheet and you should be fine.

For example **broken link removed** is a pretty common / low-cost IC that might be suitable, see **broken link removed** for more types. Most shops that sell these, have suitable coils to go with them.