YS50 is not YS110

I had created an Arduino based controller that would monitor my camera hot shoe X contact and then fire a YS50 strobe based upon a power setting level control.

I had been using some old spare Sea & Sea YS50 strobes for my testing since I did not want to damage or wear out my real strobes. It was now time to hook the Arduino up to my real Sea & Sea YS110 strobes. I expected success since I was not doing anything too sophisticated. I got utter and total failure. The YS110s did not fire consistently and did not produce a consistent power output.

Apparently YS50 and YS110 can not be controlled the same.

I was prepared for some minor small differences. The Sea & Sea TTL Converter hinted that there was differences across the various Sea & Sea strobes since it had a control that was used  to select the type of strobe attached to it (cryptically labeled A, B, C, D). I had seen images of newer converters that had labels for: YS110a, YS-01, YS-D1. This indicates that the various strobes needed to be treated differently by the converter.

But how different could they be? For backwards compatibility all of the strobes needed to support manual firing of the strobe by shorting the X signal to ground. All of the modern strobes supported the same 5 wire cable and connector.

I had presupposed that each strobe may have slightly different signal timing requirements due to variations in internal circuitry. The obvious difference would be the delay required in asserting the Q signal in order to produce the same power output. The different strobes had different Xenon flash tubes (the YS110 has 3, the others only 1) and most likely different internal capacitors.

My obvious short list of differences were all timing based:

  • duration to assert X to ensure the strobe reliably fired
  • duration to assert Q to ensure the strobe reliably quenched
  • the duration to delay Q assertion to map to a specific power level

These issues all made sense and could be handled easily by knowing which strobe was attached. The actual values could be determined easily via a set of experiments with each different strobe type I owned.

My first experiment with the YS110 revealed the problem was much different than I had imagined. The YS110 was reacting much differently than the YS50. After firing, the YS50 would turn on the red Ready light and pull the X line high after the strobe had recharged. The recharge delay could be anywhere from 1/2 a second to several seconds depending upon the power setting and battery level. The YS110 was pulling the X line high "immediately" after firing. Before it had recharged. Before the red Ready light was turned on. The scheme I used to determine if the YS50 was ready to refire did not work with the YS110. I could not tell if the YS110 was ready by watching the X signal line.

This proved that the YS50 and YS110 signaling were fundamentally different.

Seems I did not pay enough attention. YS50 are ancient. They use a 4 wire connection. The YS110 is much newer and uses a 5 wire connection. Both strobes had Ground, X and Q signal lines. Seems like the other lines maybe important?

Next step is to find out how to control a modern strobe...