Photo Multiplier Tube (PMT) Controller
<p dir="ltr">The Janelia PMT Controller is an updated design for use in high-performance microscopy systems. It was designed and built to meet the needs of the new <a href="https://www.janelia.org/open-science/2-photon-random-access-mesoscope" target="_blank">large field of view 2 photon random access mesoscope</a>, also available via license or <a href="https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=10646" target="_blank">purchase</a>. You can find the complementary PMT Amplifier <a href="https://www.janelia.org/open-science/pmt-amplifier" target="_blank">here</a>.</p><p dir="ltr">The PMT Controller provides two channels of control for GaAsP Photo Multiplier Tubes. The low–noise design uses static logic, linear power supplies, and an AC line filters. The control voltages are independently adjustable over their entire range via a multi-turn control, with the voltages displayed on the built-in meters. Each PMT can be switched on and off independently. A trip circuit is built in to detect high PMT currents. Trip level and duration can be independently set for each channel. A trip condition turns off both PMTs and can be reset via a front panel control. External control of high voltage and trip reset are also provided.</p><p dir="ltr"><b>Hardware Development</b></p><p dir="ltr">Engineers took care to eliminate switching noise in the controller, so only the panel meters use switching electronics. The trip detects circuits have some high-frequency noise filters (~30kHz), followed by a level comparator with an adjustable threshold, followed by an adjustable trip delay circuit. A trip detection occurs when the input signal reaches a particular threshold and lasts a certain duration. The two trip signals are OR’ed together to create a single trip event if either input satisfies the trip requirements. This, in turn, sets a latch to turn off the high voltage control and a trip indicator LED. The trip condition can be reset using the Trip Reset switch. Each channel can be turned on and off independently, and there is a common high voltage control.</p><p dir="ltr"><b>Use</b></p><p dir="ltr">Free to make for Non-Profit Research by downloading designs at GitHub link. <b><u>Please cite this DOI.</u></b><br>Commercial licenses are also available, contact innovation@janelia.hhmi.org and reference this DOI. </p><p dir="ltr"><br></p><p dir="ltr"><b>Other</b></p><p dir="ltr"><i>Supersedes Flintbox ID: Janelia</i><i> </i><i>2017-017</i><br><br>Link to <a href="https://www.janelia.org/open-science/pmt-controller-and-power-supply" rel="noreferrer" target="_blank">Janelia Open Science Page</a></p>
