powering the 9114B Disk drive by AC only ... thoughts?

[Gene]

Andy: I power my cassette drive using a variable DC power supply set to ~5V. I connect it to the cassette by clipping aligator clips to the battery contacts. It powers the tape drive perfectly. I'm certain you could do the same thing with the 9114 (if you still have it). Just figure out the voltage that the battery was.

Gene: I'm thinking of trying to run my HP-IL 9114B disk drive using a scheme similar to the one above. Does anyone here have the power information to know what I should buy to do this? I have an HP-IL drive, but no battery.

Ideas? Help!

[Vieira, Luiz C. (Brazil)]

Hi;

for a better, stable operation AND to maintain the unit working with a power loss, I'd suggest you to build a mini UPS, say, a power supply with rechargeable batteries inside and a convenient power charger and power monitor. You could use it connected to the AC line or not, depending on both indicators: the 9114B itself (the three-LED's indicator) and, if you decide so, the one built in the UPS.

I believe four 1,600mAH NiMH batteries would do fine, as the original 9114B battery pack uses acid-type (gel) batteries. That's why the User's Manual suggests operating the unit with the charger constantly connected to the AC line, as it haoppens with car batteries.

Think that you may be writing data to the disk at a power loss. No harm for the equipment, and as mentioned before, no harm to the midia itself. You'll have to repeat the procedure, no matter. As the HP41 is portable and operates free of AC line, I think the 9114B should also be as portable.

My US$ 0.05

Luiz C. Vieira - Brazil

[Christof]

I think in the end I'd prefer the 6V SLA over nicads .. partly because it will operate so well with trickle charging.

In fact, i've though about how hard it would be to switch the printer over to a similar system....

[Vassilis Prevelakis]

Vieira, Luiz C. (Brazil) wrote:

> I believe four 1,600mAH NiMH batteries would do fine, as the original 9114B battery 

> pack uses acid-type (gel) batteries. 

Here we go again.

If a machine uses lead-acid batteries then the charging ciruit is incompatible with NiMH batteries.

We have been through this before. The only reason that the 9114 battery pack doesn't blow up in your face is that the wimpy HP charger cannot deliver enough current.

If you go to a decent battery shop, you will be able to buy lead-acid batteries in all kinds of sizes. Although Panasonic no longer sells that particular size, there are equivalent batteries from other vendors (e.g. Powersonic), or you can use a slightly smaller battery that will fit in the battery pack.

Now, assuming you do not have an original battery pack (which means that you lack the charging cicruit as well).

In this case, I'd recommend either a bench power supply, or a battery pack (which you can charge separately, i.e. not connected to the 9114).

I wouldn't use a 12V power supply (as sold in e.g. Radio Shack) because some of them are not meant to drive electronics directly. Such power supplies are used to power 12V devices like car radios that have circuitry that stabilizes the power input.

**vp

[Vieira, Luiz C. (Brazil)]

Hi, Vassilis;

I based my sugestion on using the NiMH cells only with the complete external charger, as you may read in my post's paragraph right before the one you mentioned. I'd never suggest using the NiMH in place of the lead-acid; charging charactereistics are different, I know. My suggestion for the 1,600 mAH was for the current delivery (I'm even not sure if spin motor start current will be held by the NiMH cells; have an idea?), and I did not express this worriness completely, as you mentioned.

I agree with the fact that this particular issue should be clearly expressed, as you have surely done.

Thank you and best regards.

Luiz C. Vieira - Brazil

[Christof]

no battery... does that mean no battery holder?

if you have a battery holder, you could do what I just now finished doing - hook up a larger 6V SLA battery external to the case.

even without, the same thing can be done.

I suppose it's no problem to use the power supply straght in to the machine, though.