Can I kill a BBD circuit by starving it for voltage?

[Rodgre]

A few times I have used a chorus or flanger with a dying battery and the craziness that ensues is kind of awesome. Weird random LFO stuff, non-linear sweep and howling/squealing/whistling sounds.

My head tells me that I can damage the device by starving it with underpowering it, but I'm really curious, if technically, I can get away with it. Thoughts?

This has happened to me with a Boss BF-2 and DC-2. Very interesting "wrong" effects. Maybe I should do it with a Behringer pedal instead?

Roger

[teej212]

according to beavis you should be fine

[PRR]

> My head tells me that I can damage the device by starving it

Highly unlikely.

[blueduck577]

> Highly unlikely.

I cannot think of any application that would be damaged from a lack of voltage. I'd hate to derail the topic, but is there any circuit that could genuinely be damaged due to lack of voltage? My intuition tells me no.

[nexekho]

> Highly unlikely.

I cannot think of any application that would be damaged from a lack of voltage. I'd hate to derail the topic, but is there any circuit that could genuinely be damaged due to lack of voltage? My intuition tells me no.

A poorly designed microcontroller?  (as some pointer write/read may fail and the operation occurs in 00000000 instead)

[cpm]

> Highly unlikely.

I cannot think of any application that would be damaged from a lack of voltage. I'd hate to derail the topic, but is there any circuit that could genuinely be damaged due to lack of voltage? My intuition tells me no.

well, if your voltage drops low enough, and have a bigger input than rails, some transistor (or ICs with them inside) might be damaged if not protected... i guess

[amptramp]

I cannot think of any application that would be damaged from a lack of voltage. I'd hate to derail the topic, but is there any circuit that could genuinely be damaged due to lack of voltage? My intuition tells me no.

Switching power supplies can be damaged by insufficient voltage and brownout conditions.  Imagine a supply putting out 30 volts at one amp = 30 watts.  If you supply it from 120 volts, it takes 0.25 amps (ignoring losses).  If the source voltage drops to 90. the input has to go up to 0.333 amps, which may exceed the rating of certain parts.  Because of the feedback, the supply will attempt to draw enough current to provide the 30 watt output.  If the supply voltage goes down, the current goes up, so a lot of inverter IC's have an input voltage detector that shuts the inverter doen if voltage is too low.

Also, the input ot a regulated switching inverter shows a negative resistance characteristic, so if you have a noise filter in series, the positive impedance of the filter had better be less the the magnitude of the negative resistance of the inverter or you get an oscillator.  In this case, the negative resistance of the inverter is the 120/0.25 = -480 ohms.  With the input at 90 volts, the resistance is 30/0.33 = -270 ohms, which explains why some power supplies have exaggerated ringing or transient problems at low voltages.

[PRR]

> there any circuit that could genuinely be damaged due to lack of voltage? My intuition tells me no.

Argument: All circuits start from cold-off and work with nominal voltage. Power supply can not come up instantly. The circuit must pass through all voltages from zero to nominal, at first power-up, and again at every power-up and power-down. Therefore there must not be any "instant damage".

Counterargument: I _can_ think of some convoluted examples. HIGH-power tubes need 10V for filament and 8000V for plate. They are normally run with 10V until filament is fully warm before the 8000V is applied. If somehow the supply sagged to 5V and 4000V, the 5V would not warm the filament enough to loosen electrons, yet the 4000V would be enough to bodily YANK electrons (and whole atoms) out of the filament. I have seen an elevator controller with dozens of relays; when the "28V" sagged to 18V, it could get stuck in UP and DOWN at the same time, pop the motor breaker. I can think of others. But they are VERY far removed from the gear we would use in pedals.

In pedal-world, the most likely "damage" is the circuit HOWLS at maximum strength, starts cooking your speaker. Most stage-amps will stand full-power for considerable time; in hi-fi and PA apps sometimes tweeter-death comes quick.