Thread: Modem UT300R2U power down, dc adapter 10v dc 550ma

My BSNL Dataone connection fails within 15 minutes of working. The DC adapter stops after 15 or 20 minutes. and restarting after some time. What will be the reason ? Do anybody knows it...? Please help... If this is because of the DC adapter problem, can I replace it with a 12v DC 1a adapter ? Will it make any trouble ?

Are you sure it is a DC adapter ?
In the unit do you see any polarity marked ?
Inner pin +ve outer negative etc for the output jack?

Probably if the Electrolytic Condenser ( Cost Rs 5 to Rs 10 ), is
replaced the unit( modem) may function in stable mode.

AC adapter: 9 VAC, 1000 mA (120 VAC/60 Hz or 230 VAC/50
Hz input)
•
Power consumption: < 10.0 watt

REF:
UT300R2U

If it is a DC adapter, Usually 10Volts DC output not
available. Use adapter 220VAC/output 9VDC at 1AMP.

Any other user/s of this modem please confirm adapter details. .

Change the modem before warrenty expires..

Originally Posted by NISSAVINIS

Change the modem before warrenty expires..

Hi, i am using a Type I BSNL modem. My modem o/p 10V 550mA is down. I am trying to replace it with a new one, but the new one doesnt work for me. I tried with another modem with 12V/1A output. Its working fine, but i am worried, if it will damage my modem. Can you please advice me?

Originally Posted by Mohammed Umar S

Hi, i am using a Type I BSNL modem. My modem o/p 10V 550mA is down. I am trying to replace it with a new one, but the new one doesnt work for me. I tried with another modem with 12V/1A output. Its working fine, but i am worried, if it will damage my modem. Can you please advice me?

OK. Some basic understanding of electricty.

What is the difference between Voltage and Current?
Voltage is supplied in full whereas current is drawn as per requirement.

Suppose a device specification is 12V DC / 0.5 A. In this case, you have to have a supply that is exactly 12V DC. The current rating must be at least 0.5A or higher.

Such a power supply will always provide the right voltage and the device will draw the current that is required. If the PS is capable of providing more than 0.5A that does not mean all the current will flow into the device. The device will draw 0.5A and no more.

So in your case, there is no problem.

This works for any device. Check the voltage/ampere/wattage requirement. The Power supply must be exactly the same voltage and ampere/wattage of PS must exceed the desired requirement.

The equation is:

W = V x I.

@mpjans
@mohamad umar s

1.One model of UT300R2U needs 9V 1AMP AC supply .see annexure
Inside the modem this is rectified and with IC regulators the final
D.C voltage can be even 5V.D.C ( Beetel 220BX needs only 5V.D.C
adaptor)

2.If you connect 12VD.C output, same AC to D.C rectifier circuit
will pass the D.C as it is and final requirement is adjusted in the modem.

3.If the Power Adaptor does not get hot very soon, the current rating is OK.

4.10V ( D.C or A. C ?)at 550ma is not normally used in any modem power adaptor.

5.See the adaptor. If you see a picture of the connector jack to modem
marked +ve or _ve the out put is D.C ( usually china make )
for an A.C output a simple ~ will appear. ( no polarity)

6. My AC adaptor supplied by BSNL for AX MT 882 shows
Input 230V ~ 50 Hz 70ma
Output 9V ~ 1000ma.

7. As stated above higher current rating is preferred.
Voltage 9V or 12 V can be A.C or D.C

8. Post screen shot of your Device status.
http://i36.tinypic.com/2lizm2b.jpg

Hi,
I am using Type II modem (DNA-A211-I), having a power rating :10V dc@750mA. The adapter provided along has gone bad and i cant find adapter with same specification. I bought a new one though having 12v DC @800mA, which sometimes work and sometime doesnt. Does any body know wat altrnative rating could work.

12V DC @800mA

Reqd 10V DC at 550ma

OPTION A:

Connect it to a stabilised power supply.
May be the unit you purchased
is giving unregulated
output.

OPTION B:
You can try a three terminal (IC voltage Regulator)
as per POLARITY7909 0r 7908 -ve
or7808 0r 7809 +ve output.
DC out put from adapter to
center usually earth or common
In and out put terminals.
May cost about Rs 5 or 10/ =
Wait ....... let me check the numbers.



Condensers optional. OBSERVE POLARITY

OPTION C:
The old one. Open it
will find a small transformer diodes and electrolytic
condenser.
( condenser gone Bad ? ) replace it. cost Rs 5 to Rs 10/=

If SMPS type ( without transformer ) you will find an IC as shown above. may be faulty.

Option D:
Replace new adapter with Regulated 9V 1 AMP
unit.

I got a new one 9v DC @1000mA/1A(edited). Its working fine for me.
Ne ways thanx for the suggestions....

Originally Posted by himanshumall

I got a new one 9v DC @1mA. Its working fine for me.
Ne ways thanx for the suggestions....

1mA???????

Originally Posted by mpjans

My BSNL Dataone connection fails within 15 minutes of working. The DC adapter stops after 15 or 20 minutes. and restarting after some time. What will be the reason ? Do anybody knows it...? Please help... If this is because of the DC adapter problem, can I replace it with a 12v DC 1a adapter ? Will it make any trouble ?

what happened to the adopter given by BSNL?
If you can Get a 10V 1 amp smps type adopter, it is best. By the way check the DC voltage of your present adopter. if it is 12V DC, consult a local repairer and check the possibility of reducing it to 10V.
If you may indicate the make and model number, and whether it is screw type or sealed version, perhaps I can cross check.

in my case i have a supply made by UTS1 and the spec is 10V DC 550mA and screwed type.

Generally SMPS is better. if your has higher voltage the observation you are having is possible.