Power supply - Importance of amp Rating?

In summary, the conversation discusses the possibility of using a 110 V input power supply rated at 7.5 V DC 1,000 ma with a TV tuner that requires a DC 7.5 volt, 500 ma power supply. The analogy of a vacuum cleaner in a 15 amp circuit is used to explain the safe usage of the power supply. The electrician advises against using the power supply, but it is determined that as long as the voltage is the same, there should be no problems.
  • #1
Van Robertson
1
0
Power supply -- Importance of amp Rating??

Hello all: I have a TV tuner that requires a DC 7.5 volt, 500 ma power supply. I have a 110 V input power supply rated at 7.5 V DC 1,000 ma. Can I safely use this powersupply with the tuner. Analogy: I can plug a 3.5 am vacuum cleaner into a 15 amp circuit and know that on this 110V A/C circuit, the amperage means that you cannnot simultanously plug in devices collectively drawing more than 15 amps. Likewise, can I safely plug in a 7.5 v 500 ma device into a 7.5 v 1000 ma circuit, and not risk eventual burn-out? An electrician tokld me the tuner would eventually burn out, although it is running fine now. Is he right?
 
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  • #2


A tuner drawing 500 ma at 7.5 volts dc can run safely on a 7.5 volts dc, 1000 ma supply. Bob S
 
  • #3


Van Robertson said:
Hello all: I have a TV tuner that requires a DC 7.5 volt, 500 ma power supply. I have a 110 V input power supply rated at 7.5 V DC 1,000 ma. Can I safely use this powersupply with the tuner. Analogy: I can plug a 3.5 am vacuum cleaner into a 15 amp circuit and know that on this 110V A/C circuit, the amperage means that you cannnot simultanously plug in devices collectively drawing more than 15 amps. Likewise, can I safely plug in a 7.5 v 500 ma device into a 7.5 v 1000 ma circuit, and not risk eventual burn-out? An electrician tokld me the tuner would eventually burn out, although it is running fine now. Is he right?

I would assume that the TV tuner requires a smooth DC source such as from a battery. I don't know what your 7.5V 1000mA supply consists of, but it should probably not be a wall-wart type supply since that would likley produce a lot of ripple voltage instead of a nice smooth DC supply. Your assumption which compares the vacuum cleaner in a residential 15 amp circuit is correct. I hope that the 'electrician' is simply someone who calls himself that. I wouldn't take any advice from someone who tells you this.
 
  • #4


The power supply is rated to supply up to 1000mA therefore it can supply any amount of current up to 1000mA. You only need 500mA of power so you will be OK. The important thing is that the voltage is the same and therefore you should have no problems.
http://www.calibrepower.co.uk"
 
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1. What is the significance of amp rating in a power supply?

The amp rating of a power supply is an important factor to consider as it determines the amount of electrical current that can be supplied to a device. This is crucial because if the amp rating is too low, it may not be able to provide enough power for the device to function properly. On the other hand, if the amp rating is too high, it can potentially damage the device by delivering too much electrical current.

2. How does the amp rating affect the performance of a power supply?

The amp rating directly affects the performance of a power supply as it determines the maximum amount of electrical current that can be delivered. If the device requires more current than what the power supply is capable of providing, it may cause the device to malfunction or shut down. Therefore, it is important to match the amp rating of the power supply to the requirements of the device.

3. Can a higher amp rated power supply be used for a device that requires a lower amp rating?

Yes, a higher amp rated power supply can be used for a device that requires a lower amp rating. The device will only draw the amount of current it needs, so there will be no harm to the device. However, it is not recommended to use a lower amp rated power supply for a device that requires a higher amp rating as it may not be able to provide enough power and can potentially damage the device.

4. What happens if the amp rating of a power supply is exceeded?

If the amp rating of a power supply is exceeded, it can lead to overheating and potentially damage the power supply or the device. This is because the power supply is trying to deliver more current than it is designed for, which can cause it to overwork and fail. It is important to always use a power supply with an amp rating that meets or exceeds the requirements of the device.

5. How can I determine the correct amp rating for a power supply?

The correct amp rating for a power supply can be determined by checking the specifications of the device. The device will typically have a minimum amp rating that is required for it to function properly. It is important to choose a power supply with an amp rating that meets or exceeds this requirement. In case of uncertainty, it is recommended to consult a professional or the manufacturer of the device.

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