DC Voltage and Current Requirements

[techfuzz]

5V ±5%, 12V ±5%

The above describes a CDRW that I have. Can I assume that it is using between 4.75W-5.25W and 1A on the 5V rail and 11.4W-12.6W and 1A on the 12V rail or am I interpreting these numbers incorrectly?

techfuzz

 

[talshiar99]

5% of 12V is 0.6V
From what you listed above it says nothing about the current. Look in the manual at the back where it has tech specs it will give you Max current and normal operating current.

 

[CTho9305]

Um, I think those requirements mean that it won't operate on voltages that are more than 5% off 12 and 5V. You need to find different numbers (specifically the currents it draws, which are not necessarily related to operating voltages the way you think)

 

[techfuzz]

See that's the problem, I did look and nowhere does it say what the current draw is. It just lists the +5V and +12V deviations that I gave you guys. I only assumed it was using 1A since it wasn't explicitly specified. I know next-to-nothing about electrical engineering standards and conventions. Are there any other numbers I can look for that I'm not aware of?

techfuzz

 

[CTho9305]

What drive?

 

[techfuzz]

Originally posted by: CTho9305
What drive?

Yamaha CRW2100E (16x10x40x) and Lite-On LTN-483S (48X)

techfuzz

 

[sgtroyer]

The CRW2100E manual specs the following power consumption numbers:

11W writing or reading
4W standby - during disk spindown
1W sleep - combined with computer's power saving

It doesn't say what the breakdown between 12V and 5V is.

I couldn't find numbers for the Lite-On.

 

[techfuzz]

Originally posted by: sgtroyer
The CRW2100E manual specs the following power consumption numbers:

11W writing or reading
4W standby - during disk spindown
1W sleep - combined with computer's power saving

It doesn't say what the breakdown between 12V and 5V is.

That's where the 5V ±5%, 12V ±5% question comes in.

techfuzz

 

[blahblah99]

Originally posted by: techfuzz

Originally posted by: sgtroyer
The CRW2100E manual specs the following power consumption numbers:

11W writing or reading
4W standby - during disk spindown
1W sleep - combined with computer's power saving

It doesn't say what the breakdown between 12V and 5V is.

That's where the 5V ±5%, 12V ±5% question comes in.

techfuzz

That +- junk is just telling the consumers and power supply designers that the device is guaranteed to work within those voltages. Anything out of that range will stress the components in the device, or not provide sufficient voltage. As for current consumption, I suppose you can just tack on a ammeter.

 

[PowerEngineer]

Originally posted by: sgtroyer
The CRW2100E manual specs the following power consumption numbers:

11W writing or reading
4W standby - during disk spindown
1W sleep - combined with computer's power saving

It doesn't say what the breakdown between 12V and 5V is.

I couldn't find numbers for the Lite-On.

Given this information (and assuming that the larger power consumption would logically be drawn from the 12 volt supply), I'd say you would be safe to assume that the current draw on either supply should be less than 1 amp. Why is this important to you?

 

[techfuzz]

Originally posted by: PowerEngineer
Given this information (and assuming that the larger power consumption would logically be drawn from the 12 volt supply), I'd say you would be safe to assume that the current draw on either supply should be less than 1 amp. Why is this important to you?

I'm trying to get a handle on the total power consumption of all my computer components for a discussion on power supplies and spec'ing the proper ones based on my systems. I had no clue what those +- things were and if I could infer power consumption from them.

On another note, I emailed Lite-On asking them the specs on my CD-ROM, turns out they "no longer provide power specifications on that model". Sounds like some Tech Support guy was too bothered to look up the information for me. So I asked them the same question about more recent model that would be supported and got half my question answered. They conveniently left out the current and wattage requirements for the individual +5V and +12V rails. I sent them back an email asking for more information, but that was late last night probably after they left for the evening. If I eventually get the answer I'm looking for, I'll let everyone know.

techfuzz