550EX flash whine normal?

[tim]

My 550EX constantly emits a high pitched whine the entire time it's switched on. Its pitch and volume change depending on whether it's charging or fully charged, but it's always there. Is this normal? It's quite annoying.

[defordphoto]

'Tis normal.

[tim]

Thanks Jim. I thought it was but it was worth checking.

[robertwgross]

Normally, you will hear the noise while it is charging up. Then, once charged, (on mine, at least) the noise should stop.

Two possibilities here. Either your hearing is very good, or your flash unit is marginal. For example, if the main charge capacitor is funky, or if the oscillator circuit that charges the main capacitor is funky, or if the voltage detector circuit that detects when the main capacitor is fully charged is funky, then the noise may continue.

What would cause the main capacitor to be funky? Large electrolytic capacitors can get funky if they "dry out". This could be caused by a failed seal on the capacitor component, or it could be from a prolonged period of storage without any use at all, or maybe it just failed by chance. Storage outside the rated temperature limits could do it, too.

"We'll ship no whine before it's time."

---Bob Gross---

[tim]

Thanks Bob. I just did a little test - I put in fresh standard batteries, it charged up, the lamp went red, then the whine stopped. I put my NiMH back in, the light never went red - they must be a bit flat. I put in charged NiMH batteries and they worked the same as the standard batteries, just a little slower.

Question answered and problem solved, thanks :)

[robertwgross]

By "standard", I assume you mean alkaline.

You will get slightly different charging performance depending on whether you use alkaline or NiMH or lithium primary or anything else. Each different type has a different terminal voltage. Then whether the battery is new or used will make a lot of difference.

Many photographers use NiMH batteries for a 550EX. This is especially true if the flash is getting a lot of use. The NiMH batteries can be recharged many times.

I, however, use three sets of alkaline batteries during the course of one wedding.

When the charging whine goes rather silent (on mine, at least), I suspect that the whine is still there, but it is inaudible to most humans. Animals hear it, though, so I try to be aware of this when doing night wildlife photography.

---Bob Gross---

[tim]

Yep, alkaline. I use high capacity NiHM batteries, saves buying batteries, though I got a 40 pack of no-brand alkaline for around US$10 a while back I still have quite a few of.

Do you use them for the faster charge rate Bob?

[robertwgross]

The type of batteries I use depends on what price I had to pay for them. If good alkalines are cheap enough, then I like to have plenty around. If cheap NiMH cells are good enough, then I like to have some of those in the charger also, but I go to places where recharging is a problem. For long, important trips where recharging is a problem and weight is a problem, then I take lithium primary cells.

The only problem becomes all the different types of batteries involved. I have to have some BP-511s charged up for my camera. I have to have AAs for the flash units. I have to have 123s for the film camera. Then there are a few other diverse kinds.

If I ever get out of photography, I'll likely try to invent a universal battery.

---Bob Gross---

[pradeep1]

For future sake when someone does a search to find this problem, the 420EX also makes this whine. I actually returned a flash unit to Adorama to get another one, and it did the same thing....so that must be a "feature" of Canon flashes above 420EX.

[Ballen Photo]

For future sake when someone does a search to find this problem, the 420EX also makes this whine. I actually returned a flash unit to Adorama to get another one, and it did the same thing....so that must be a "feature" of Canon flashes above 420EX.All my flashes seem to whine right up to the point that the capacitor is fully charged, at which point they stop whining. This includes my 550EX, 380EX, Vivitar 283, Sunpak 544, and a couple Pentax units. I think this is normal for all accessory flash units. Glad to hear you found the problem Tim. :)
PS, I no longer own the 380EX or the Sunpak 544.
-Bruce