AC-DC Adapters & Power Cords

Voltage is the specification with no room in it. Transcell instruments run at 6, 9 or 12 V DC depending on the model, and an adapter one step up is not a conservative choice, it is an over-voltage.

The three voltages are not distributed randomly. 6 V covers the TI-500 family, the FDI readouts, the RF kits and the WB5040-AWP weigh beams. 9 V covers both a set of legacy bench scales and, in the universal versions, the TI-500E. 12 V covers the SPS-30 and DCS bench ranges at 500 mA, and at 1000 mA a much wider list including the TI-500 SL, the TI-500 RF SS and the WB5040-SWP.

If the old adapter is present, its label settles the question in two seconds and is worth more than any table on this page. If it is missing, the instrument model number gets you there instead: every adapter here names the products it powers, and the fitment table below is that information collected in one place.

One thing not to infer: two instruments in the same family can take different voltages. The WB5040-AWP takes 6 V while the WB5040-SWP takes 12 V, because the stainless model carries a rechargeable pack and the aluminium one does not. Same product line, different supply.

Current is the specification people get wrong in the safe direction, and it is worth understanding why the asymmetry exists.

An adapter's milliamp or amp rating is the most it can deliver, not what it forces into the instrument. The instrument draws what it needs. So a 9 V 3 A adapter will run a device that draws 500 mA perfectly happily; it simply spends its life at a sixth of its capability.

The other direction is where the damage is. A 9 V 100 mA adapter asked to supply 500 mA runs hot, its output voltage sags under load, and the instrument sees a supply that drops every time the backlight or the serial port draws current. The symptom is rarely a dead scale; it is an unstable reading, an instrument that resets when it prints, or a display that dims. Those look like faults in the scale, which is why this one costs so much time to diagnose.

The practical rule: match or exceed the original rating, never fall below it. Where the catalog offers the same voltage at several currents, the higher one is always a safe substitution and the lower one never is.

This is the specification that catches experienced people, because it is invisible in a product title read quickly.

At 9 V alone the catalog has a 100 mA male connector, a 200 mA female connector, a 500 mA male connector and a 600 mA female barrel. Two of those are male and two female, and the voltage tells you nothing about which.

The generational logic behind it is worth knowing: the older bench ranges, the ESW, ESR, SPS-5, SPS-10, TC-100, MCS and EL series, generally take a male connector, while the current TI-series indicators take a female barrel. The one product page that says this outright is the 9 V 200 mA, which fits the newer-style SPC series specifically, with the older style taking the 100 mA part instead.

Four of these adapters share one product photo, so go by the product title, which names the connector as male or female, or send us the instrument model and let us pick it.

The ten adapters split into two kinds, and the difference only matters when the instrument leaves the country.

The fixed adapters are moulded units with US pins and a fixed output lead. Simple, cheap, and tied to a US outlet.

The universal adapters, the 9 VDC 2.5 A, the 9 VDC 3 A and the 12 VDC 2 A, accept worldwide input and take a detachable mains cord. Each ships with a US cord included, and the EU and UK cords are stocked separately at $15 each. Shipping an instrument to Europe therefore means adding a cord, not sourcing a different power supply.

Which US cord ships with which adapter is stated on the products themselves: the 9 VDC 2.5 A and 12 VDC 2 A include a NEMA 1-15, while the 9 VDC 3 A includes a NEMA 5-15.

Before replacing an adapter, it is worth asking whether the instrument should be running from one.

On a washdown or stainless installation, the external adapter is the component that is not sealed. The enclosure can be NEMA 4X and the adapter still sits in a wet room on the end of a lead. The internal power supply option moves the supply inside the housing and removes it from the environment entirely, which is a reliability improvement rather than a tidiness one.

On a portable or field instrument, the answer may be the NP3-6 rechargeable pack instead. The TI-500 SL, TI-500 BWL and WB5040-SWP are built around it, and an adapter on those is a charger rather than the running supply.

And where the instrument travels between benches, a longer output lead is usually the wrong fix; a second adapter left permanently at each station costs $25 and removes the daily unplugging that eventually breaks the barrel socket.