User's Manual

P330 Data Sheet / User Guide 33
DRAFT
Charger/supply
Anker 10W (2A) Home and Travel USB
Wall Charger Adapter
Table 4-2: Accessory source information
WARNING: In practice, USB devices are not provided with a uniform level of quality. The devices
listed above work well and are recommended. The same cannot be said about other USB devices.
Some suppliers of cables use undersized wiring that is so small that it is not capable of providing
sufficient power to the P330s. Some produce power with a great deal of ripple. We have even seen
outputs with 1v spikes on a 5 volt signal! This is not acceptable for driving the P330s.
Some batteries and power supplies have very poor connectors. These connections are so flimsy that
they provide power only intermittently. Consider the devices shown in Figure 4-19. The connector
on the left provides a high quality connection with multiple contact points. The one on the right has
few contact points and will cause endless problems. Nothing will ruin a multiday measurement
campaign more completely than a few cheap, worthless USB cables and connections.
Fig. 4-19: Superior connections (left) and inadequate product (right)
When providing power from USB devices do NOT use USB extension cables. There is sufficient
voltage drop across these cables that they will not provide sufficient power to drive a P330.
Two sets of pins guarantee a good connection
Nothing to insure a proper connection