Are the Flupic/POP2 regulation boards or are they just programmable UIs?

Do they boost voltage, regulate current etc or do they just allow dimming/strobe?

See this post from Goldserve:
https://www.candlepowerforums.com/posts/1048226&postcount=15
They are elsewhere described as current regulated also.

Bernie

Current 'regulated' via LDO.

In short, they regulate max current via the current limit in the LDO regulator. Cheers!

Thanks! What exactly is the LDO?

what are the LDO mAh set at?

Randy Shackleford said:

what are the LDO mAh set at?

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Check out post #134 over in goldserve's thread (https://www.candlepowerforums.com/threads/112678).

Here's the POP/POP2 threads:
PIC-O-PWM (POP) micro-P DIY & Video
POP2 (PIC-O-PWM V2) with PICmicro Dual UI

Although the LDO's have built-in current limits, they vary from sample to sample. A tps732xx LDO has a minimum current limit of 250ma, 425ma typical and 600ma max. Only way to know the exact value is to check it yourself.

in the spec sheets, they are more like 350, 450 and 700. TI underestimates their ratings by a huge margin...which is kudos!

Here's an esay way of thinking of these:

The driver is essentially a switch between the battery and the emitter. The switch is controlled by a microcontroller to allow for things like PWM dimming and other functions such as strobe/SOS/beacon. In the case of the FLuPIC and POP implementations the switches limit the maximum current that passes through them. The Low Drop Out (LDO) moniker comes from the fact that the "switches" do this without dropping the voltage very much.

One of the great things about these FLuPICs and POPs is that the uC driven LDO essentially removes the problem of significantly overdriving the emitter.

A variant of this implementation is the LDO part being replaced by a MOSFET. The benefit of using a MOSFET is that one can be chosen with a very low "on resistance" value. The problem with using a MOSFET is the maximum current is not limited and the Vf of the emitter must be close to the battery voltage or the emitter current will be very high. Some current implementations of this configuration have reported emitter currents in the 1800mA range!

HTH,

Paul

goldserve said:

in the spec sheets, they are more like 350, 450 and 700. TI underestimates their ratings by a huge margin...which is kudos!

Click to expand...

My point exactly. With my samples though, they're well within the specs given in the datasheet.

Btw, are these your actual measured values?

Thanks for the info Goldserve. A volts in high of 3.6V ~ 4.8V is an important restriction.

With a nice low VF like TWOh or a RED coloured led, you could drive it using the flupic with a 3V battery and it will work just fine. Any input voltage lower than the led's VF + 0.15V will be direct driven.

Are the lower output levels current regulated?

While we're at it, what's the highest current available for "high" (not burst)? Can I set high to 1000mA?

Bernie

If I understand correctly, dimming is done by PWM, not current regulation. So the highest brightness available is when PWM is 100%, thus the max current allowed by the LDO all the time.

Kryosphinx said:

Are the lower output levels current regulated?

Click to expand...

Sort of... Irregardless of output level, the LDO's current limit still applies.