04-02-2015, 07:57 PM
(04-01-2015 04:15 PM)Marcus von Cube Wrote: [ -> ]Whenever a computation takes longer than a fraction of a second, the speed is increased (in two steps) up to the maximum speed of some 30 MHz.
Even in SLOW mode?
(04-01-2015 04:15 PM)Marcus von Cube Wrote: [ -> ]Whenever a computation takes longer than a fraction of a second, the speed is increased (in two steps) up to the maximum speed of some 30 MHz.
(04-02-2015 07:57 PM)John Galt Wrote: [ -> ]Even in SLOW mode?
Quote:@Marcus: Do you know the voltage threshhold at which the calculator resets?
(04-02-2015 07:19 PM)Bernd Grubert Wrote: [ -> ]@Marcus: Do you know the voltage threshhold at which the calculator resets?
(04-02-2015 09:39 PM)John Galt Wrote: [ -> ]I performed some measurements that may interest you. The WP 34S will run reliably all the way down to 2.35 V.Thanks for providing the voltage values. This means that a large capacitor might help. If e.g. the residual voltage of a weak battery is 2.8V a voltage drop of 0.45 is tolerable. If the capacitor has an internal resistance of 30 Ohm and 1.5F capacity, it can deliver 10mA for about 22s until the voltage gets below threshold.
(04-03-2015 09:59 PM)John Galt Wrote: [ -> ]OK, but why do you need 22s? The capacitor required will be enormous.No, it is not. It's dimension are 19mm dia. x 5mm height. A little bit more than the batteries that are use inside the HP 30B.
(04-03-2015 09:59 PM)John Galt Wrote: [ -> ]I think you would be better off installing bigger batteries, but that's just my opinion. I don't intent to discourage experimentation, I enjoy doing that myself.May be you're right, but I don't want to use AAAA-batteries. Taking apart 9V batteries and soldering them in anytime you have to replace the batteries seems uncomfortable to me.
(03-31-2015 09:02 AM)Bernd Grubert Wrote: [ -> ]What about adding a gold cap as a back-up power source for demanding calculation?My experiences with super capacitors are limited to double-layer capacitors (EDLCs). In general, they are great to deliver the relatively high-energy peak currents observed f.e. in conjunction with GSM wireless modems, however, I have found them to be not without their own set of shortcomings as well.
(04-04-2015 07:40 AM)Bernd Grubert Wrote: [ -> ]This is exactly my thinking as well.(04-03-2015 09:59 PM)John Galt Wrote: [ -> ]I think you would be better off installing bigger batteriesMay be you're right, but I don't want to use AAAA-batteries. Taking apart 9V batteries and soldering them in anytime you have to replace the batteries seems uncomfortable to me.
(04-05-2015 05:06 PM)matthiaspaul Wrote: [ -> ](04-04-2015 07:40 AM)Bernd Grubert Wrote: [ -> ]May be you're right, but I don't want to use AAAA-batteries. Taking apart 9V batteries and soldering them in anytime you have to replace the batteries seems uncomfortable to me.This is exactly my thinking as well.